Experiences with
Insulin

Insulin is a hormone made in your pancreas, which is a gland behind the stomach. It helps your body use glucose (sugar) for energy.

When your pancreas is working properly it makes small amounts of insulin all the time and releases more insulin when your blood glucose levels increase after eating. When you have diabetes, your body does not make enough insulin or the insulin it makes does not work properly.

Everyone with type 1 diabetes, and some people with type 2 diabetes or gestational diabetes, needs to take insulin to help manage their blood glucose levels. This reduces the chances of getting the symptoms of high blood glucose (hyperglycaemia) and serious long-term problems that can damage the heart, kidneys, eyes, nerves and feet.

Rapid-acting insulin is a type of very fast-acting insulin. This means it starts to work very quickly and you take it before meals to stop your blood glucose from going too high when you eat carbohydrates.

Rapid-acting insulin is sometimes also known as bolus insulin or mealtime insulin.

Unless you use an insulin pump, you'll usually take rapid-acting insulin along with another type of insulin called intermediate-acting insulin or long-acting insulin. This is taken once or twice a day and gives you the background insulin you need when you're not eating.

Rapid-acting insulin is available on prescription only. It comes as:

pre-filled pens
cartridges that you use in a reusable insulin pen
cartridges that you use in an insulin pump
a solution in a vial (a small bottle) for injecting or using in a pump

Who can take rapid-acting insulin

Most adults and children with diabetes can take rapid-acting insulin.

Who may not be able to take rapid-acting insulin

Rapid-acting insulin may not be suitable for some people.

To make sure it's safe for you, tell your doctor if you've ever had an allergic reaction to insulin or any other medicine.

Dosage

Rapid-acting insulin usually contains 100 units of insulin per 1ml of liquid, but some brands are also available containing 200 units of insulin per 1ml of liquid. Make sure you know what strength of insulin you're taking.

You'll usually take a dose of rapid acting insulin around 10 to 15 minutes before each meal. Your doctor or diabetes nurse will advise you on when to take it. The exact timing may depend on which brand you take. See what timing works best for you and try to stick to it as closely as possible.

Taking it before meals means that your levels of insulin are highest as your body absorbs glucose from the meal, which helps to stop your glucose level from going too high.

Your doctor or diabetes nurse will tell you how many units of insulin you'll need to take. You'll usually need to calculate your dose depending on the amount of carbohydrate food (sugar and starches) in each meal. This is known as carb counting. If you have type 1 diabetes you'll be given training in how to do this.

The dose of rapid-acting insulin you need also depends on:

your weight
the type of diabetes you have
how active you are
whether you're taking other medicines for diabetes

Changes to your dose

As well as adjusting your dose for what you eat, you may also need to change your dose:

when you're ill
if you're stressed
in hot or cold weather
if you're doing exercise
when you start or stop some medicines
during the menopause
if you're pregnant
while you're growing if you're a child or young person
if you're fasting (for example during Ramadan or for other religious reasons)
if you change your daily routine, for example if you're doing shift work

It's a good idea to keep a record of the amount of insulin units you inject if possible.

Testing your blood glucose

Testing your blood glucose regularly will help you and your diabetes healthcare team know if you're taking the right dose for you. Your doctor or diabetes nurse will explain how to do this.

Diabetes UK has more information and videos about checking blood glucose levels.

Most people take rapid-acting insulin using an insulin pen or a pump. The type of pen you'll use depends on which brand of insulin you've been prescribed. There are different types of pre-filled pens, reusable pens and pumps so check the instructions for the type you're using.

If you use vials and syringes to inject instead of a pen, your diabetes nurse will show you how to do this.

Using an insulin pen

When you start taking insulin your diabetes nurse will show you how to use your pen to inject. Always follow the instructions for your pen.

Using an insulin pen does not usually hurt. The needles are very small as you only inject a small amount into the layer of fat just under your skin.

Wash your hands.
Attach a new needle to your pen every time you inject.
Remove any air from your pen by turning the dial to 2 units of insulin, pointing the pen up into the air and pressing the plunger until insulin starts to come out of the needle. If no insulin comes out then do this again.
Dial your dose of insulin by turning the dial on the pen to the correct number.
Choose a place to inject on your tummy, the sides of your thighs or your buttocks – make sure you use a different place each time.
Hold the pen at a right angle to your skin and push the needle into your skin.
Push the plunger in slowly, then hold the pen in place for 10 seconds to make sure you get the full dose.
Take the pen out of your skin, remove the used needle and put it in your sharps bin, then put the cap back on your pen.

It's important to vary the places you inject so that you're less likely to get fatty lumps under your skin (lipohypertrophy). Although these are usually harmless, they can mean that insulin is not always absorbed at the same speed when you inject into them. This can affect your blood glucose levels.

Diabetes UK has more information and videos showing how to inject insulin.

Rapid-acting insulin can also be taken using an insulin pump, which you attach to your body.

An insulin pump is a small device you wear all the time that delivers short acting or rapid-acting insulin throughout the day and night.

Insulin flows into your body from the pump through a tiny tube (cannula) which you insert under your skin.

Using a pump means you do not have to take injections, and you can easily adjust the dose to get the amount of insulin you need. Pumps can help to improve your blood glucose levels compared to injections. Most people find their blood glucose does not go too high or low as often.

The pump is programmed to deliver tiny amounts of insulin over 24 hours to give you the background insulin you need. This means you do not need a separate intermediate or long-acting insulin. You also use the pump controls to give a larger dose before meals.

When you start using a pump, you'll be shown how to initially programme and adjust the pump settings to change the insulin dose, and how to change the cartridge or fill the insulin reservoir in the pump, attach the infusion set to the pump, prime the pump to remove any air, and attach the infusion set to your body.

There are 2 types of pump:

tethered insulin pumps – these use a thin tube to connect the pump to the cannula. You'll need to replace the cannula every 2 to 3 days, moving it to a different place on your body each time, usually on your tummy or thighs. You can carry the pump on your belt, in your pocket, or in a body band
patch insulin pumps – these have no extra tubing and are attached directly to your body with adhesive, usually on your arm, leg or tummy. They're disposable and need to be replaced every 2 to 3 days. You control the pump using a separate hand-held device

Pumps are available on the NHS to:

adults and children aged 12 years old and over with type 1 diabetes who have severe hypos, or whose blood sugar levels are too high despite carefully trying to manage their diabetes
children aged under 12 years old who cannot easily take multiple daily injections

They're not usually available on the NHS for people with type 2 or gestational diabetes.

It's important to always take the right amount of insulin. To avoid making any mistakes with your insulin dose:

make sure you know the name and strength of the insulin you use, and always check you have the right one
make sure you know your usual dose and how to adjust it when you need to
if you take 2 types of insulin, double check the type and dose each time you inject – you could keep the pens in separate places so that you do not mix them up
get advice on your injection technique from your diabetes nurse
if you're admitted to hospital, make sure the staff know about your insulin treatment

If you have a problem with your insulin pen

Insulin pens are designed to stand up to a lot of wear and tear. But they can sometimes become faulty, and this can affect your blood glucose levels.

If you're concerned that your pen is not reliably giving the right dose of insulin, contact your doctor or diabetes nurse for advice.

How long to take it for

If you have type 1 diabetes you'll need to take insulin for your whole life.

If you have type 2 diabetes you'll need to take insulin if other treatments for diabetes are not reducing your blood glucose enough. Once you start taking insulin it's likely that you'll need to take it for the rest of your life, provided it improves your blood glucose and you cope well with the treatment.

If you're taking insulin to treat gestational diabetes you can usually stop taking it once your baby is born, as the condition usually goes away after you give birth.

It's important to take insulin as recommended by your doctor or nurse. Speak to them if you have any problems with taking it.

When your blood glucose is well managed you're less likely to get the short-term symptoms of high blood glucose (hyperglycaemia) such as blurred vision, needing to pee more, tiredness and feeling very thirsty. You're also less likely to get serious long-term problems that can damage your heart, kidneys, eyes, nerves and feet.

Stopping insulin suddenly can lead to severe hyperglycaemia and a life-threatening condition called diabetic ketoacidosis.

If you have any concerns about your insulin treatment, talk to your diabetes specialist, doctor or diabetes nurse.

If you forget to take it

Taking too little insulin increases the risk of high blood sugar (hyperglycaemia) and long-term complications from diabetes.

If you forget to take your rapid-acting insulin before a meal, and you've already eaten, consider taking a slightly smaller dose or correction dose, or contact your doctor or diabetes nurse for advice.

Look out for any signs of high or low blood glucose levels, and check your blood glucose levels more often than usual. Contact your doctor or diabetes nurse if you're concerned.

Never take 2 doses to make up for a forgotten dose.

If you take too much

Taking too much insulin can make your blood sugar go too low, causing hypoglycaemia (a hypo). You might also have a hypo if you:

miss or delay meals or have not had enough carbohydrates
do lots of exercise without having the right amount of carbohydrates or reducing your insulin dose
drink alcohol, especially after skipping a meal

Symptoms of a hypo

Symptoms of low blood sugar include:

sweating
trembling or shaking
anxiety, confusion or difficulty concentrating
fast heartbeat (palpitations)
tingling lips
changes to your vision such as blurred vision
feeling dizzy
feeling hungry
paler than usual skin

It's also possible for your blood sugar to go too low while you're asleep. If this happens, you may wake up at night feeling sweaty and confused, or you may feel tired or have a headache in the morning. Speak to your diabetes team if you think you might be having hypos at night.

These symptoms happen when your blood glucose falls below 4 mmol/L.

Treating a hypo

If you get hypo symptoms, follow the instructions you've been given to treat a hypo:

Have a sugary drink or snack, such as a small glass of fruit juice or sugary fizzy drink, 5 glucose or dextrose tablets, 4 large jelly babies, or 2 tubes of glucose gel.
Check your blood glucose after 10 to 15 minutes. If it's improved and you feel better, move on to step 3. If it's still low, have another sugary drink or snack, then check your blood glucose again after 10 minutes.
Once you blood glucose is back above 4mmol/L, eat a starchy carbohydrate that lasts longer in your blood, like a sandwich or some biscuits, or your next meal if it's due.
Once you feel better and your blood glucose is back under control, you can restart your insulin treatment.

Always carry glucose tablets or high sugar snacks with you in case you have a hypo.

Do not drive, cycle or use machinery if you've taken too much insulin, even if you do not have symptoms. If you have a hypo, do not drive for at least 45 minutes after you've recovered.

Try to make sure someone stays with you if you've taken too much insulin.

If you have very low blood glucose (a severe hypo) you may become drowsy or unconscious. Make sure your family or friends know what to do if this happens, including how to give a glucagon injection, and when to call 999 for an ambulance.

Storing insulin at home

Your doctor or diabetes nurse will work out how much insulin you need to have at home to last you 1 or 2 months. Always try to have at least one spare pen, cartridge or vial available to use.

Keep your disposable insulin pens, cartridges or vials in the fridge until you start using them. Keep them away from the freezer section or cooler element inside the fridge. If the insulin freezes you'll need to throw it away.

Insulin that you're using

Once you start using a new disposable pen or cartridge, you can keep it out of the fridge at room temperature for up to 4 weeks.

Injecting cold insulin straight from the fridge can be painful, so it's best let it warm up to room temperature before you use it.

Keep your insulin pen out of direct sunlight and away from radiators. If it gets too warm the insulin may not work properly.

Rapid-acting insulin that has been kept out of the fridge for longer than 28 days may not work properly, so you'll need to return it to your pharmacy to dispose of it. You can write the date that you took it out of the fridge on the packaging, to help you remember.

Travelling with insulin

Taking insulin will not stop you from travelling, but it's important to plan ahead.

If you're away from home, it's a good idea to take an extra supply of insulin with you.

If necessary, keep it in a cool bag while travelling, but be careful not to put it next to an ice block so that it does not freeze.

If you're going on holiday:

pack extra medicine – speak to your diabetes nurse about how much to take
find out how you can get insulin in the place you're visiting, and take a recent prescription with you
carry your insulin in your hand luggage if you're flying
take a letter from your GP or diabetes care team to say you have diabetes and need to take your insulin and your equipment such as insulin pens and needles onto the plane (you may need to pay for the letter)
let the airline know well in advance if you use an insulin pump or a glucose monitor (a sensor that you wear attached to your body to check your blood glucose) – you can also download a medical device awareness card from the Civil Aviation Authority website
if you'll be crossing several time zones, ask your doctor or diabetes nurse how to adjust your insulin doses

Common side effects

There are things you can do to help cope with these common side effects of rapid-acting insulin:

Insulin can make your blood glucose levels fall too low (hypoglycaemia, or hypos).

Symptoms include:

sweating
trembling or shaking
anxiety, confusion or difficulty concentrating
fast heartbeat (palpitations)
tingling lips
changes to your vision such as blurred vision
feeling dizzy
feeling hungry
paler than usual skin

If you start to get some of these symptoms, follow the instructions you've been given to treat a hypo and have a sugary drink or snack, such as such as a small glass of fruit juice or sugary fizzy drink, 5 glucose or dextrose tablets, 4 large jelly babies, or 2 tubes of glucose gel.

This type of sugar will not last long in your blood, so you may also need to eat a starchy carbohydrate once you blood glucose is back above 4mmol/L, like a sandwich or some biscuits, or your next meal if it's due.

You can reduce the chances of having a hypo by monitoring your blood glucose levels regularly and adjusting your insulin dose as advised by your doctor or diabetes nurse.

If you often get hypos, ask your doctor or diabetes nurse about getting a continuous glucose monitor or flash monitor, if you do not already have one.

This is a small sensor you wear on your skin that can show your blood glucose levels at any time. Most types have an alarm, which can wake you up if you get a hypo while you're asleep. You may be able to get a monitor free on the NHS.

Talk to your doctor or diabetes nurse if you often get hypos, or if you get them at night. It's likely you'll need to adjust your insulin treatment.

Try to avoid using any new soaps or bath products in the first few weeks of treatment, so that you'll know if any itching is caused by the insulin.

You can take an antihistamine to help ease the itching. Ask a pharmacist what type is suitable for you.

Itching and redness usually improves after about a week. If it does not get better, contact your doctor or diabetes nurse, as you may need to switch to a different type of insulin.

Always use a new needle for every injection. Rotate your injection sites by choosing a different place each time you inject, at least 1cm away from your last injection. You can use your tummy, the sides of your thighs or your buttocks.

Let your insulin warm up to room temperature before using it.

It can also help to try numbing the injection area by rubbing it with ice for 15 to 20 seconds before you inject.

If the pain does not stop or bothers you, contact your doctor or diabetes nurse to check your injection technique and make sure you're using the right size needle. Insulin needles come in different lengths, and a slightly longer or shorter needle could be better for your body shape.

Some people have some minor bleeding after injecting but this is not usually a problem. To reduce bruising, gently press the injection site for a few minutes after each injection.

If bleeding or bruising does not stop or bothers you, contact your doctor or diabetes nurse to check your injection technique and make sure you're using the right size needle. Insulin needles come in different lengths, and a slightly longer or shorter needle could be better for your body shape.

This can happen if you repeatedly use the same small area of your body to inject. It can look unsightly and can affect how the insulin is absorbed into your body.

To help reduce the chances of this happening, rotate your injection sites by choosing a different place each time you inject, at least 1cm away from your last injection. You can use your tummy, the sides of your thighs or your buttocks.

If you do get these lumps, do not inject in that area until it becomes soft and smooth again. This can take several weeks.

You may notice problems with your eyesight when you first start taking insulin, but this usually only lasts a short time.

Diabetes can also affect your vision, so you may have noticed your eyesight getting worse before you start insulin. You may find that your eyesight improves after a week or two as your blood glucose levels improve.

If it does not improve or you feel your eyesight is getting worse, speak to your doctor or diabetes nurse.

If you have diabetes you're eligible for free NHS sight tests.

If you've been diagnosed with diabetic retinopathy and you feel your eyesight is getting worse, contact your doctor or diabetes nurse.

Speak to your doctor or diabetes nurse if the advice on how to cope does not help and a side effect is still bothering you or does not go away.

Serious side effects

Insulin can sometimes cause severe hypos, where your blood glucose falls very low and you can become unconscious.

Speak to your doctor or diabetes nurse if:

you've had severe hypos
you do not always recognise the symptoms when you have a hypo

You think someone's having a severe hypo and they're not responding normally or they're unconscious, and:

a glucagon injection is not available or you do not know how to use it
you've given a glucagon injection and they have not recovered within 10 minutes
they've been drinking alcohol

In rare cases, it's possible to have a serious allergic reaction to rapid-acting insulin (anaphylaxis).

Meds New IA (H4) - serious allergic reaction

These are not all the side effects of rapid-acting insulin. For a full list, see the leaflet inside your medicine packet.

Rapid-acting insulin and pregnancy

You can take rapid-acting insulin while you're pregnant.

It's important that diabetes is well treated in pregnancy as regularly having blood glucose levels outside of your target range can be harmful to both you and your baby.

If you take insulin and are planning a pregnancy or become pregnant, it's important to speak to your doctor or community midwife. They'll help make sure your treatment is right for you and advise you on any changes to your dose that you may need during pregnancy.

You'll usually be seen in a specialist diabetes antenatal clinic, which will advise you on blood glucose monitoring, monitoring of your baby and your insulin dose.

It's common to need an increase in your insulin dose as pregnancy progresses.

Rapid-acting insulin and breastfeeding

You can take rapid-acting insulin while you're breastfeeding if you have type 1 or type 2 diabetes.

If you had gestational diabetes during pregnancy, you will not usually need insulin once you've given birth, as your condition will usually disappear when your baby is born.

It's important that diabetes is well treated while breastfeeding as regularly having blood glucose levels outside of your target range can make it more difficult to get started with breastfeeding and can affect the amount of milk you make. Taking insulin can help with these problems.

You may need less insulin while breastfeeding than you did in pregnancy. Your doctor or diabetes nurse will help make sure your treatment is right for you and advise you on any changes to your dose that you may need while breastfeeding.

Each time you breastfeed you lose sugar through your breast milk, so your blood glucose level falls. Your diabetes nurse will talk to you about extra snacks you might need to help stop your blood glucose levels going too low and causing a hypo.

Insulin is naturally found in breast milk, and rapid-acting insulin will also pass into breast milk. Insulin is essential for the healthy development of your baby. The amount that passes across into breast milk is very unlikely to cause any unwanted effects in your baby.

If you notice that your baby is more sleepy than usual, seems paler than usual, sweaty or shaky, or if you have any other concerns about your baby, call 111 or talk to your doctor, pharmacist, health visitor or midwife as soon as possible.

Rapid-acting insulin and fertility

There's no evidence that rapid-acting insulin affects fertility in either men or women.

Meds New IA (H2) - Pregnancy non-urgent care card

Cautions with other medicines

Some medicines can increase your blood glucose levels and some can reduce your levels. You might need to adjust your insulin dose if you start or stop these medicines.

Always check with your doctor, diabetes nurse or pharmacist when starting or stopping a medicine.

Medicines that can reduce your blood glucose levels include:

any other medicines used to treat diabetes, such as metformin, dapagliflozin, empagliflozin, pioglitazone, gliclazide, glimepiride, alogliptin, linagliptin, saxagliptin, sitagliptin, semaglutide, dulaglutide, liraglutide or exenatide
angiotensin converting enzyme (ACE) inhibitors, used to treat high blood pressure and heart failure, such as enalapril, ramipril or perindopril
anabolic steroids such as testosterone

Medicines that can reduce your blood glucose levels and reduce your awareness of the symptoms of hypos include beta blockers such as atenolol, propranolol or metoprolol. These are used to treat conditions including high blood pressure and heart disease. You'll need to carefully monitor your blood glucose if you're taking beta blockers.

Medicines that can increase your blood glucose levels include:

thiazide diuretics (medicines that make you pee more) such as bendroflumethiazide, used to treat high blood pressure and build-up of fluid
steroid tablets and steroid injections, such as dexamethasone, prednisolone or hydrocortisone, used to treat inflammatory conditions and allergies (steroid creams that you put on your skin will not generally affect your blood glucose)
levothyroxine, used to treat thyroid disease
contraceptive pills

Mixing rapid-acting insulin with herbal remedies and supplements

Many herbal remedies are advertised to help control diabetes and some have been shown to reduce blood glucose levels. If you take insulin, never start or stop taking a herbal remedy without getting advice from your doctor, pharmacist or diabetes nurse.

It's not possible to say that any herbal remedies and supplements are safe to take with insulin. They're not tested in the same way as pharmacy or prescription medicines. They're generally not tested for the effect they can have on other medicines.

Meds New IA (H2) - Cautions with other medicines alert

Insulin is a hormone made in your pancreas, which is a gland behind the stomach. It helps your body use glucose (sugar) for energy.

Short-acting insulin (sometimes called regular insulin, soluble insulin or neutral insulin) starts to work quickly, and you take it before meals to stop your blood glucose from going too high when you eat carbohydrates.

Short-acting insulin is sometimes also known as bolus insulin or mealtime insulin.

Unless you use an insulin pump, you'll usually take short-acting insulin along with another type of insulin, called intermediate-acting insulin or long-acting insulin.

Short-acting insulin is available on prescription only. It comes as cartridges that you use in a reusable insulin pen and as a solution in a a small bottle (vial) for injecting or using in a pump.

Who can take short-acting insulin

Most adults and children with diabetes can take short-acting insulin.

Who may not be able to take short-acting insulin

Short-acting insulin may not be suitable for some people.

To make sure it's safe for you, tell your doctor if you've ever had an allergic reaction to insulin or any other medicine.

Dosage

Short-acting insulin contains 100 units of insulin per 1ml of liquid.

You'll usually take a dose of short-acting insulin around 30 minutes before each meal. Your doctor or diabetes nurse will advise you on when to take it. The timing may depend on which brand you take. See what timing works best for you and try to stick to it as closely as possible.

Taking it before meals means that your levels of insulin are highest as your body absorbs glucose from the meal, which helps to stop your glucose level from going too high.

The dose of short-acting insulin you need also depends on:

your weight
the type of diabetes you have
how active you are
whether you're taking other medicines for diabetes

Changes to your dose

As well as adjusting your dose for what you eat, you may also need to change your dose:

when you're ill
if you're stressed
in hot or cold weather
if you're doing exercise
when you start or stop some medicines
during the menopause
if you're pregnant
while you're growing if you're a child or young person
if you're fasting (for example during Ramadan or for other religious reasons)
if you change your daily routine, for example if you're doing shift work

It's a good idea to keep a record of the amount of insulin units you inject if possible.

Testing your blood glucose

Testing your blood glucose regularly will help you and your diabetes healthcare team know if you're taking the right dose for you. Your doctor or diabetes nurse will explain how to do this.

Diabetes UK has more information and videos about checking blood glucose levels.

Most people take short-acting insulin using an insulin pen or a pump. There are different types of pens and pumps so check the instructions for the type you're using.

If you use vials and syringes to inject instead of a pen, your diabetes nurse will show you how to do this.

Using an insulin pen

When you start taking insulin your diabetes nurse will show you how to use your pen to inject. Always follow the instructions for your pen.

Using an insulin pen does not usually hurt. The needles are very small as you only inject a small amount into the layer of fat just under your skin.

Wash your hands.
Attach a new needle to your pen every time you inject.
Remove any air from your pen by turning the dial to 2 units of insulin, pointing the pen up into the air and pressing the plunger until insulin starts to come out of the needle. If no insulin comes out then do this again.
Dial your dose of insulin by turning the dial on the pen to the correct number.
Choose a place to inject on your tummy, the sides of your thighs or your buttocks – make sure you use a different place each time.
Hold the pen at a right angle to your skin and push the needle into your skin.
Push the plunger in slowly, then hold the pen in place for 10 seconds to make sure you get the full dose.
Take the pen out of your skin, remove the used needle and put it in your sharps bin, then put the cap back on your pen.

Diabetes UK has more information and videos showing how to inject insulin.

Short-acting insulin can also be taken using an insulin pump, which you attach to your body.

An insulin pump is a small device you wear all the time that delivers short-acting or rapid-acting insulin throughout the day and night.

Insulin flows into your body from the pump through a tiny tube (cannula) which you insert under your skin.

There are 2 types of pump:

tethered insulin pumps – these use a thin tube to connect the pump to the cannula. You'll need to replace the cannula every 2 to 3 days, moving it to a different place on your body each time, usually on your tummy or thighs. You can carry the pump on your belt, in your pocket, or in a body band
patch insulin pumps – these have no extra tubing and are attached directly to your body with adhesive, usually on your arm, leg or tummy. They're disposable and need to be replaced every 2 to 3 days. You control the pump using a separate hand-held device

Pumps are available on the NHS to:

adults and children aged 12 years old and over with type 1 diabetes who have severe hypos or whose blood sugar levels are too high despite carefully trying to manage their diabetes
children under 12 years old who cannot easily take multiple daily injections

They're not usually available on the NHS for people with type 2 or gestational diabetes.

It's important to always take the right amount of insulin. To avoid making any mistakes with your insulin dose:

make sure you know the name and strength of the insulin you use, and always check you have the right one
make sure you know your usual dose and how to adjust it when you need to
if you take 2 types of insulin, double check the type and dose each time you inject – you could keep the pens in separate places so that you do not mix them up
get advice on your injection technique from your diabetes nurse
if you're admitted to hospital, make sure the staff know about your insulin treatment

If you have a problem with your insulin pen

Insulin pens are designed to stand up to a lot of wear and tear. But they can sometimes become faulty, and this can affect your blood glucose levels.

If you're concerned that your pen is not reliably giving the right dose of insulin, contact your doctor or diabetes nurse for advice.

How long to take it for

If you have type 1 diabetes you'll need to take insulin for your whole life.

If you're taking insulin to treat gestational diabetes you can usually stop taking it once your baby is born, as the condition usually goes away after you give birth.

It's important to take insulin as recommended by your doctor or nurse. Speak to them if you have any problems with taking it.

Stopping insulin suddenly can lead to severe hyperglycaemia and a life-threatening condition called diabetic ketoacidosis.

If you have any concerns about your insulin treatment, talk to your diabetes specialist, doctor or diabetes nurse.

If you forget to take it

Taking too little insulin increases the risk of high blood sugar (hyperglycaemia) and long-term complications from diabetes.

If you forget to take your short-acting insulin before a meal, and you've already eaten, consider taking a slightly smaller dose or correction dose, or contact your doctor or diabetes nurse for advice.

Look out for any signs of high or low blood glucose levels, and check your blood glucose levels more often than usual. Contact your doctor or diabetes nurse if you're concerned.

Never take 2 doses to make up for a forgotten dose.

If you take too much

Taking too much insulin can make your blood sugar go too low, causing hypoglycaemia (a hypo). You might also have a hypo if you:

miss or delay meals or have not had enough carbohydrates
do lots of exercise without having the right amount of carbohydrates or reducing your insulin dose
drink alcohol, especially after skipping a meal

Symptoms of a hypo

Symptoms of low blood sugar include:

sweating
trembling or shaking
anxiety, confusion or difficulty concentrating
fast heartbeat (palpitations)
tingling lips
changes to your vision such as blurred vision
feeling dizzy
feeling hungry
paler than usual skin

These symptoms happen when your blood glucose falls below 4mmol/L.

Treating a hypo

If you get hypo symptoms, follow the instructions you've been given to treat a hypo:

Have a sugary drink or snack, such as a small glass of fruit juice or sugary fizzy drink, 5 glucose or dextrose tablets, 4 large jelly babies, or 2 tubes of glucose gel.
Check your blood glucose after 10 to 15 minutes. If it's improved and you feel better, move on to step 3. If it's still low, have another sugary drink or snack, then check your blood glucose again after 10 minutes.
Once you blood glucose is back above 4mmol/L, eat a starchy carbohydrate that lasts longer in your blood, like a sandwich or some biscuits, or your next meal if it's due.
Once you feel better and your blood glucose is back under control, you can restart your insulin treatment.

Always carry glucose tablets or high sugar snacks with you in case you have a hypo.

Do not drive, cycle or use machinery if you've taken too much insulin, even if you do not have symptoms. If you have a hypo, do not drive for at least 45 minutes after you've recovered.

Try to make sure someone stays with you if you've taken too much insulin.

Storing insulin at home

Your doctor or diabetes nurse will work out how much insulin you need to have at home to last you 1 or 2 months. Always try to have at least one spare cartridge or vial available to use.

Keep your insulin cartridges in the fridge until you start using them. Keep them away from the freezer section or cooler element inside the fridge. If the insulin freezes you'll need to throw it away.

Insulin that you're using

Once you start using a new cartridge, you can keep it out of the fridge at room temperature for either 4 or 6 weeks, depending on which brand you're using. Check this with your diabetes nurse or pharmacist.

Injecting cold insulin straight from the fridge can be painful, so it's best let it warm up to room temperature before you use it.

Keep your insulin pen out of direct sunlight and away from radiators. If it gets too warm the insulin may not work properly.

Short-acting insulin that has been kept out of the fridge for longer than the recommended time may not work properly, so you'll need to return it to your pharmacy to dispose of it. You can write the date that you took it out of the fridge on the packaging, to help you remember.

Travelling with insulin

Taking insulin will not stop you from travelling, but it's important to plan ahead.

If you're away from home, it's a good idea to take an extra supply of insulin with you.

If necessary, keep it in a cool bag while travelling, but be careful not to put it next to an ice block so that it does not freeze.

If you're going on holiday:

pack extra medicine – speak to your diabetes nurse about how much to take
find out how you can get insulin in the place you're visiting, and take a recent prescription with you
carry your insulin in your hand luggage if you're flying
take a letter from your GP or diabetes care team to say you have diabetes and need to take your insulin and your equipment such as insulin pens and needles onto the plane (you may need to pay for the letter)
let the airline know well in advance if you use an insulin pump or a glucose monitor (a sensor that you wear attached to your body to check your blood glucose) – you can also download a medical device awareness card from the Civil Aviation Authority website
if you'll be crossing several time zones, ask your doctor or diabetes nurse how to adjust your insulin doses

Common side effects

There are things you can do to help cope with these common side effects of short-acting insulin:

Insulin can make your blood glucose levels fall too low (hypoglycaemia, or hypos).

Symptoms include:

sweating
trembling or shaking
anxiety, confusion or difficulty concentrating
fast heartbeat (palpitations)
tingling lips
changes to your vision such as blurred vision
feeling dizzy
feeling hungry
paler than usual skin

If you start to get some of these symptoms, follow the instructions you've been given to treat a hypo and have a sugary drink or snack, such as a small glass of fruit juice or sugary fizzy drink, 5 glucose or dextrose tablets, 4 large jelly babies, or 2 tubes of glucose gel.

You can reduce the chances of having a hypo by monitoring your blood glucose levels regularly and adjusting your insulin dose as advised by your doctor or diabetes nurse.

If you often get hypos, ask your doctor or diabetes nurse about getting a continuous glucose monitor or flash monitor, if you do not already have one.

Talk to your doctor or diabetes nurse if you often get hypos, or if you get them at night. It's likely you’ll need to adjust your insulin treatment.