Do supplement manufacturers need to be FDA-registered or GMP-certified?

Yes. U.S. dietary supplements must be produced under FDA 21 CFR Part 111 cGMP rules, and a reputable manufacturer should be FDA-registered, GMP-certified, and provide third-party testing for potency, heavy metals, and microbial safety. AJ Cosmo Labs surfaces supplier certifications and documentation in their profiles so you can verify compliance and request a Certificate of Analysis directly.