Synthroid vs levo: What is the difference between... - Thyroid UK

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Synthroid vs levo

Teresamarie profile image
16 Replies

What is the difference between the name brand Synthroid and generic levo?

Thanks for any ideas. Will Synthroid help symptoms of excess sweating and insomnia? I’m just going bonkers! Presently on 75 mg levo

Teresa

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Teresamarie profile image
Teresamarie
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16 Replies
shaws profile image
shawsAdministrator

Synthroid is the 'brand' name and the usual levothyroxine we get prescribed in UK is a generic version. This is a link which is self-explanatory. An excerpt:

"There are branded levothyroxine preparations (ie SynthroidTM, LevoxylTM) as well as generic preparations. While the FDA has deemed generic and branded preparations equal, this has been based on short-term studies in healthy adult volunteers and not long-term treatment of hypothyroid patients. In infants with severe congenital hypothyroidism, even small changes in thyroid hormone levels may have negative effects on their development. Few clinical studies have been performed to date to determine whether generic and branded levothyroxine preparations are truly equal in patients with hypothyroidism. In this study, generic and branded levothyroxine preparations are compared as treatment in a group of hypothyroid children".

thyroid.org/patient-thyroid...

Teresamarie profile image
Teresamarie in reply toshaws

Hi shaws

Thanks for your explanation of generic vs name brand T4. Is there a difference between name brands to each other? I’m central hypo with a great sensitivity to meds. I’m now trying name brand vs levo to help with symptoms.

Teresa

shaws profile image
shawsAdministrator in reply toTeresamarie

I believe that there can be differences in brands or generics. It can be trial and error, unfortunately.

Teresamarie profile image
Teresamarie in reply toshaws

Thanks again shaws. I’ll be sure to get the same name brand each time. I’m so frustrated with this whole process but understand it’s the only way. I’m really hoping for some positive changes.

Coachgeorge profile image
Coachgeorge in reply toTeresamarie

I’m right there with you. This is a terrible journey but we will get there.

helvella profile image
helvellaAdministrator in reply toTeresamarie

There are differences between all makes, but there are also differences between batches of the same make. (The exception is where a single product is sold in two ways - e,g. Lannett is the same product as Unithroid.)

There is nothing fundamentally better about Synthroid rather than, say, Lannett (Unithroid). The important things are:

Make sure you always know what you are being dispensed.

Keep to the same product.

Only change if it is intentional.

It is a good idea to be aware of the ingredients. If you find a make that you do not like, perhaps you react adversely to, then consider if one or other of the excipients (inactive ingredients) is the cause. Thinking this through might help to explain what is going on.

You can find all USA makes in some detail here:

dailymed.nlm.nih.gov/dailym...

Teresamarie profile image
Teresamarie in reply tohelvella

Hi helvella

Thanks for responding. I guess I shouldn’t be shocked that even between batches there is a difference. This thyroid stuff is not for sissies!

I’ll be sure to do as you suggest. Right now 4 days of no sleep and sweating. Just lovely!

Teresa

MaisieGray profile image
MaisieGray in reply toTeresamarie

Such variation isn't specific to Levo or any other thyroid meds; it's the case generally, with licensed/regulated drugs. Rather than being shocked that there is some variation, there is such a miniscule amount of active ingredient in tablets that it surprises me that human beings can achieve the degree of pharmacokinetic standardisation that they do achieve 🙂

This article, which references the US but the principle is the same here of course, explains the difference between brand and generic and also why the author believes there's a degree of misunderstanding about the 80-125% bio equivelance rule.

pharmacytimes.com/contribut...

helvella profile image
helvellaAdministrator in reply toMaisieGray

Even though levothyroxine in the UK is required to remain within 90 to 105% potency throughout its shelf life, I doubt many products vary by anything like that as measured in an assay. Given decent storage, I'd expect it always to be within a smaller range.

MaisieGray profile image
MaisieGray in reply tohelvella

Yes, and we know from the large FDA study of the substantial pharma stocks held by US Forces, that for most drugs (other than those acknowledged to have a short shelf life) that even up to 15 years, many remain both potent and safe, although I can't remember what parameters were used to judge potency by the researchers.

jgelliss profile image
jgelliss

I found that the fillers/dyes is what made a big difference between working well for me or experiencing symptoms .

Teresamarie profile image
Teresamarie in reply tojgelliss

Thank you for responding. I’m hopeful that the brand name may make a difference.

jgelliss profile image
jgelliss in reply toTeresamarie

Brand names may have fillers too that can have fillers that don't work well too . I was on Synthroid and had awful reactions from it . Palpitations insomnia , anxiety . I learned that it has Acacia . It's made from shrubs and trees .

verywellhealth.com/synthroi...

Teresamarie profile image
Teresamarie in reply tojgelliss

Thanks for this. This is such a long process. I’m just getting discouraged that I’ve been working on the dosage now for a year and am not doing well. All the encouragement I’ve gotten is much appreciated.

jgelliss profile image
jgelliss in reply toTeresamarie

You might want to try Levoxyl .Or even Tirosint that has no fillers at all . But because it has no fillers you might just need a little less of it .

Be Strong and Don't Give Up . You will get there with Persistence .

Sending You Positive Hugs .

Teresamarie profile image
Teresamarie in reply tojgelliss

Thanks for your words of encouragement. I’m needing them as of late.

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