Does my lack of metabolism affect my treatments?

If you are taking replacement therapy for your thyroid and your levels are normal, there should be no impact on the longevity of your fillers. Typically the fillers last 9-12 months for patients. It's wonderful that you are getting to enjoy the benefits longer!

You are taking a thyroid replacement pill and generally when you have had thyroid cancer, a little excess thyroid hormone is given to suppress the body from producing TSH which would make the cancer grow. Therefore, your metabolism as it pertains to thyroid hormone is probably higher than before and not lower. Fillers in lips are generally hyaluronic acid fillers and with time an enzyme in our body called hyaluronidase chews up the fillers and they get cleared.
Some fillers are more cross linked than others and these allow such fillers to last longer. Juvederm Vollure made with Allergan’s Vycross crosslinking technology cross-links the hyaluronic acid molecules so they are not as easily absorbed by the body. Perhaps you had vollure that lasts 1.5 years as opposed to Juvederm that last one year. Depending on the technique used, some practitioners move the needle under the skin more than others and this also stimulates your own collagen development. These factors probably play a bigger role than metabolism vis-a-vis the thyroid hormone.

I don’t think having had your thyroid gland removed has anything to do with the longevity of your lip fillers.

Occasionally we see people who have longer lasting results than anticipated.

Best,

Mats Hagstrom MD

Hi and welcome to our forum!Hyaluronic acid fillers have a longevity of about 6-12 months (some a bit longer, some shorter). Your metabolism should be normal if your replacement therapy is adequate. I am not aware of any studies suggesting altered resorption rates relating to thyroid dysfunction. The injected material is dissolved by hyaluronidase, a body enzyme.
Perhaps, another material was utilized. Hydroxyapatite injections last up to several years but are plagued with resulting lumpiness. Fat injections, tendon grafts to the lips, fascial grafts to the lips, liquid silicone injections, and prosthetic implants have also been utilized to plump the lips.
Perhaps, the filler material was replaced with scar tissue, in which case the "plumping" may be permanent!
Sorry I can't be more specific...Best wishes...