I'm 52 and have hashimotos thyroid. I had restylane 7 years ago, and would like to do it again. Would it be risky?

There are no known contraindications with hyaluronic acid fillers and Hashimotos Thyroid. When you have a consultation with an expert injector they will discuss your health history to ensure you are a candidate for the product. All the Best. 

I am currently not aware of a contraindication of Restylane and hashimotos thyroiditis.  I would need to do further research before stating that it would be safe for you to have Restylane.  

There is no known contraindication to filler injections in patients with Hashimotos's thyroiditis. In the past there was some concern about collagen fillers and autoimmune disorders, but hyaluronic acid fillers are composed of the exact same protein you already have in your skin.

The human body is remarkable in it's ability to guard itself against foreign bodies. In the case of Hashimoto's Thyroiditis, it mistakenly identifies a molecule on the thyroid as foreign and attacks this organ. This can be similar to any and all allergic syndromes whether they are external such as pollen or internal such as auto-immune thyroiditis. Restylane and similarly made HA's (hyaluronic acid fillers) are a molecule made to be bio-identical to human skin HA and therefore this molecule would have no immunogenic reaction in the body. When Restylane and other injectibles are purified for human use, there maybe micro-impurities which stimulate a allergic style response. The cross-reactivity of one molecule stimulating a immunogenic response to another molecule is even more rare.I would recommend you contact your endocrinologist or rheumatologist to see if there is any cross-reactivity between these 2 molecules or any other concerns you should consider.I anticipate the benefits will far outweigh the risks. Good luck.