I started taking 5000mcg of methyl b12 sublingual. My neuropathy symptoms became 100 times worse the pain in my feet and hands became unbearable. I stopped taking it. I feel i need to start taking them bit am so afraid of that pain starting. Can anyone tell me if this reaction gets better, or should i start on a low dose and build up gradually.
Methylated forms don't necessarily work for everyone. (Seems to be some adverse reactions between methylated forms and some of the MTHFR genetic variations.) I don't think the reaction you have had is unique but it certainly doesn't sound like a normal reaction.
Have you had methyl in other forms and not had this reaction? and have you tried supplementing other forms first? You may be better of sticking with hydroxo/cyano if those work for you. Generally you can't get sublinguals in these formats but you can certainly get hydroxo as nasal sprays.
No i have not tried other forms. The reason i went for methyl is i read cyano is not as good as it has to be coverted some how by the liver. I also read about a startup regime to try and avoid these symptoms. Have you heard of this? I don't know much about hydroxy but am willing to give it a try.
are you based in the US?
There is a lot of talk about methyl being better because it is closer to the format that is used by cells but the reality is a lot more mixed than that. I find that it does absolutely nothing for me in terms of psychiatric symptoms whereas hydroxo (used in the UK) works very well for me with those symptoms and we are talking about methyl being a form which in theory should be able to cross the brain/blood barrier - obviously there is something specific about the way my body processes the hydroxo.
some people find they got on better with cyano than hydroxo - though there are links that mean cyano may not be the best form if you smoke - or have a genetic problem called Lebers which means it can affect the optic nerve.
Cyano injections tend to be used in US, hydroxo in the UK. You may have problems getting hold of hydroxo if you are based in the US - but there are nasal sprays with cyano that might work okay - no guarantees with anything B12 though as it is one area where variation is quite wide.
I find Hydroxo works best for me, otherwise I get some depression and weird feelings.
I also had an increase of, and some new symptoms, when I started taking B12. Currently I've upped my dose to over 20 mgs and they are starting to get better.
Did you increase the dose gradually? If so what dose did you start with? I have read so many different things that i am now so confused. Do you also take other vitamins/supplements?
I know that feeling of being afraid to take more and backed off for ages, then took the plunge and within a day felt better. It may have been more sensible to go up quickly, but I didn't. Give it a few days though - I'd been on a higher dose for a little while before I backed off and had to cope with the increased pain.
I started straight away on 5000mcg i started getting pain after about 24hours. My hands and feet felt like they were on fire the pain was constant. I was not getting any sleep. Even taking strong painkillers did not touch it. I could no longer cope so stopped after 7 days. That was a month ago and it took about 3 weeks to calm down. I have read that it is a shock to the nerves to suddenly have b 12 in the system again. I feel need to start again but at a small dose and see how it goes. But might try hydroxy and hope it is more agreeable to me. I am still having neuropathy pain but not as bad.
Do different types of B12, the methyl, the hydroxo and the cyno help differing parts of the body?
Methyl or Hydro B12 injections - is it safe to switch between both each month? 
Methyl Cobalamin Injections
changing hydroxo and methyl dosage. 
