A couple of sources. These are not cheap...but probably cheaper than Rx. If you want to try some, maybe try one first and see how you feel. Currently I take Kanchanar and Triphala gugs. daily.
Bulk Kanchanar (cheaper than tablets and I prefer powders anyway). Out of stock at present.
https://www.banyanbotanicals.com/kanchanar-guggulu-powder/
https://www.banyanbotanicals.com/kanchanar-guggulu-tablets-10/
Bulk Kaishor Gug out of stock too.
https://www.banyanbotanicals.com/kaishore-guggulu-powder/
https://www.banyanbotanicals.com/kaishore-guggulu-tablets-10/
In stock in bulk:
https://www.banyanbotanicals.com/triphala-guggulu-powder/
https://www.banyanbotanicals.com/triphala-guggulu-tablets-10/
I also get herbs from this site, also reputable, both sites have organic only, and their own labs for testing. Capsules and bulk, and cheaper than Banyan.
https://vadikherbs.com/products/kaishore-guggulu-capsules
https://vadikherbs.com/products/kaishore-guggulu
https://vadikherbs.com/products/triphala-guggulu-capsules
https://vadikherbs.com/products/triphala-guggulu
https://vadikherbs.com/products/kachnar-guggulu
https://vadikherbs.com/products/kachnar-guggulu-capsules
I just ordered a 90 day supply of Kanchanar Guggulu tablets. I have two benign tumors on my thyroid. Otherwise, my thyroid is working properly. I have a family history of thyroid problems and so I want to be proactive with it. Thank you for this tip!