Whenever a particular levothyroxine tablet is mentioned, at least someone reports that they cannot tolerate it. Quite often a lot of people.
Whether it is thought (or proved) to be the lactose, acacia, mannitol, dyes (not in any UK products), microcrystalline cellulose or any other excipient (inactive ingredient).
A typical tablet might weigh over 50 milligrams. Of which, perhaps 0.2% is active ingredient.
(As an example, one particular 100 microgram tablet contains 48.86 milligrams of lactose.)
As a challenge to all our readers, imagine a pharmaceutical company asked YOU to formulate a new tablet, what excipients would you choose? It is so easy to see the issues with the currently available tablets but another thing altogether to come up with an acceptable alternative.
Obviously almost none of us know anything about the realities of manufacturing levothyroxine tablets. This is pure fantasy and for fun and discussion - but it would be good to be as realistic as possible.
I have been mulling this over for years and still can't make my mind up what I would choose.