Bioidentical hormones are biochemically similar to those produced by the body or ovaries. The FDA has approved many prescription products that contain bioidentical hormones. However, the term “bioidentical” is often used to refer to custom-compounded hormones. One major difference between FDA-approved prescription bioidentical products and custom-compounded products is that the former are regulated by the FDA and tested for purity, potency, efficacy and safety. Custom-compounded hormones allow for customization of dosing and hormone combinations.