Is one 100mcg tablet much different from two 50mcg levothyroxine tablets?

[Hoop1888]

Hi all.

I wondered if anyone had noticed a difference or know of there being a difference in effect between taking two 50mcg tablets of levothryoxine as opposed to one 100mcg tablet? I’m curious as there seems to be much chat around the effects of the filler in the tablets re different brands so wondered if any effects were observed by anyone here?

[helvella Administrator Thyroid UK]

A couple of concrete examples:

Accord 50 microgram tablets contain 39.95 milligrams of lactose. Two would have 79.9.

Whereas a 100 microgram tablet has 54.9 milligrams of lactose.

Advanz 50 microgram tablets contain 48.86 milligrams of lactose. Two would have 97.72.

A 100 microgram tablet also has 48.86 milligrams of lactose.

Therefore, if the quantity of lactose matters, or if the proportion of lactose to levothyroxine matters, there would be a real difference.

Things like rate of dissolution, other excipients (and we know nothing of the quantities of them), etc., could also be important.

There shouldn't be any difference. Because if the manufacturer or the MHRA believed there was any difference, they'd have to do something about it. Wouldn't they?

But we have had this basic question, in various precise forms, quite a few times over the years. And I think there really can be differences by tablet dosage. But I'm not convinced we can predict whether they will be the same or different.

[Hoop1888 in reply to helvella]

Thanks for that!

[helvella Administrator Thyroid UK in reply to Hoop1888]

Did it make sense?