Whilst wandering through the thyroid mine field I came across this http://www.racgp.org.au/afp/2012/august/thyroid-therapy/

[siskin]

I thought this was interesting, a bit technical but seen worse.

The whole site seems to have quite a lot of other interesting subjects as well.

[shaws Administrator]

Thanks for posting Siskin. If I was being treated as per this page, I would be quite unwell as it is mainly interested only in levothyroxine and also says about T3:

The issue of T4 versus T3 has been debated in many professional forums and the consensus seems to be that objectively, T4 therapy is better than T3 therapy.6 T3 therapy has significant disadvantages because of its short half-life (1 day compared to 1 week for T4) and daily T3 use is associated with peaks and troughs rather than the flatter profile of T4 therapy. Prescribing T3 in several divided doses through the day does flatten the profile but this is inconvenient and may not be adhered to. Research has shown that no benefit of combined levothyroxine and triiodothyronine (T3) therapy.6

Conflict of interest: none declared.

As we know many do o.k. on levothyroxine but those who don't need either T3 added or T3 only.