Difference in T3

[Brightness14]

Both Thybon Henning and Cynomel are made by Sanofi but one is 20 mcg and the other 25 mcg

does anyone know the difference in ingredients. Most people on the site appear to prefer the Thybon one. I am prescribed T3 Cynomel and it doesn't agree with me.

After being on NDT for years the fast acting T3 never works on me, is it because I have not gut problems and so it acts too fast. Even if I take 1/8 it still does the same, it never stays in my body for more than a few minutes.

I am not allergic to anything either. No Hasimotos.

[Jaydee1507 Administrator]

What were your latest blood results? 2 months ago you said your FT3 was 'rock bottom' and if you're not taking enough then no wonder you have symptoms.

Thybon Henning is lactose free whereas Cynomel does contain lactose.

It is essential to test your vitamin levels.

When hypo we get low stomach acid which means we cannot absorb vitamins well from our food, regardless of a great diet. For thyroid hormone to work well we need OPTIMAL levels of vitamins. Have you recently or could you ask your GP to test levels of ferritin, folate, B12 & D3? Private tests are available, see link for companies offering private blood tests & discount codes, some offer a blood draw service at an extra cost. thyroiduk.org/help-and-supp...

[Brightness14 in reply to Jaydee1507]

OK thanks for the information.

[helvella Administrator Thyroid UK]

Henning became part of Sanofi Deutschland a number of years ago - which was when Thybon Henning ended up a product of Sanofi. Whereas the Cynomel product is produced by Sanofi (Sanofi Aventis) in France.

They were different products, with different histories and different formulations. And different dosages!

The Cynomel trade mark is licensed from:

GLAXOSMITHKLINE LLC, Société organisée selon les lois de l'Etat du Delaware

Although it appears obvious to us that one company having two products is an odd duplication - from Sanofi's point of view it might make good sense.

Both products are listed in helvella's medicines documents (UK and Rest of the World) which can be found here:

helvella - Thyroid Hormone Medicines

helvella has created, and tries to maintain, documents containing details of all thyroid hormone medicines in the UK and, in less detail, many others around the world.

This link takes you to a page which has direct links to the documents from Dropbox and Google Drive, and QR codes to make it easy to access from phones.

The UK document contains up-to-date versions of the Summary Matrix for tablets, oral solutions and liothyronine available in the UK.

helvella.blogspot.com/p/hel...

[helvella Administrator Thyroid UK in reply to helvella]

Just to make it clear, there are links to the company documentation for both products in my documents.

[Brightness14 in reply to helvella]

OK Thanks

[helvella Administrator Thyroid UK in reply to Brightness14]

Just remembered that you might notice Sanofi Cynomel, and every other liothyronine I know of, contains Liothyronine sodium - except Thybon Henning. Which contains Liothyronine hydrochloride. Whether this makes a difference is one of the many great unanswered questions related to thyroid.

[Brightness14]

That may be the answer I will look these up. Of course I am prescribed Cynomel living in France and because I have never had any problems with taking anything I just wondered why it never suited me. I was never any good at chemistry at school so watch this space. Thank you.