There are certain supplements that support thyroid function and maintaining optimal levels. It’s important to consider other possible problems, so not just your thyroid, such as low vitamin levels and other health conditions that can cause symptoms similar to hypothyroidism.
Supplementing may help with symptoms.
I would always recommend consulting your doctor, pharmacist, a medical professional etc. before making any changes to your health regime. It can be dangerous if you take supplements and already have high/sufficient levels.
If you’re gluten or dairy free, or have any other restrictions, do also always check that all supplements you take are free of the substance, too.
Most vitamins can be tested via doctors’ tests to learn your levels.