It's not noted in the website description, but you can see it in the image: this product is not just Urolithin A. It also contains NMN, Resveratrol, and Spermidine. The Spermidine is derived from wheat germ extract, and Wheat is listed as an allergen on the label. I am not allergic to Wheat, but I do have Celiac disease. The product is labeled Gluten Free on the front, so I thought it would be safe, but I experienced stomach cramping and bloating - typical of my Celiac symptons - on the 2nd day of trying it. Obviously, I have no way of proving this was the cause, and it could be below the 20ppm limit and I'm just extra sensitive, but I'm warning anyone with Celiac Disease who are thinking of trying this particular product. Maybe try somethign else.