Levothryoxine and Progesterone

[pennyhe]

I have the Nexplanon implant (I had it inserted around 3 months ago) and was recently prescribed Levothyroxine for an under active thyroid and I know that oestrogen can affect its effectiveness but was wondering whether progesterone was the same?

[WildDeer]

Hi pennyhe,

First thing is that Nexplanon is a progestagen, not progesterone.

Progestagens vary according to which company makes them, and chemically they are very different from progesterone the female hormone . They suit some women well, particularly those who don't have a tendency towards PMS symptoms.

Here is an excerpt from the list of possible side effects: Carbohydrate Metabolic Effect

The use of progestagen-containing contraceptives may have an effect on peripheral insulin resistance and glucose tolerance. Therefore, diabetic women should be carefully monitored during the first months of Nexplanon use.

If you have any doubts about the effectiveness of the birth control, It would be best to ask your GP to check it out. It doesn't list this under contraindications though.