Hi @Sabrine Mahbouli – if your sister isn’t responding well to T4 only medication, it can be due to not being able to convert T4 to T3 properly. So it doesn’t matter how much T4 they give her, if she can’t convert it, she’ll still feel hypothyroid. T3 is the active thyroid hormone which has effect in the body.
Some people choose desiccated thyroid over Levothyroxine because it comes from animal thyroid glands (typically pigs or cows) so it tends to mimic our body’s natural thyroid hormones by containing both T4 and T3 thyroid hormones. The downside is that hormone levels in desiccated thyroid can vary between batches so dosing can be less precise.
The other option is to discuss with your functional doctor or naturopath to prescribe a compounded T3 thyroid hormone. If you don’t know any in your area, I always recommend working it backwards. Search and contact a local compounding pharmacy in your area, and ask them to give you names of functional doctors who use their pharmacy.
The next step is to help your sister figure out WHY she may not be converting T4 to T3 well enough. If you have the chance to go through the entire Thyroid Balance course, please do so. You’ll understand how to better support your sister.
Otherwise, start with these videos to ensure she has the basic minimum nutrients needed for thyroid conversion:
Foods for a Healthy Thyroid
Protect Your Thyroid
And then watch these to figure out if any of these common root cause factors are at play:
How Insulin Affects Thyroid Function
How Sex Hormones Affect Thyroid Function
How Cortisol Affects Thyroid Function
Hope this helps.