"That variability in sourcing is one of the biggest concerns, particularly when it comes to purity, dosing consistency and overall quality control." The FDA does not allow production of BPC-157, GHK-Cu, KPV and ipamorelin in the U.S., for example, by compounding pharmacies because of safety concerns , so people are ordering them from overseas usually from China
10.1016/j.jconrel.2013.01.027 240 Sadowska-BartoszI.BartoszG
10.1016/j.biomaterials.2011.05.008 59 LiF.LiW.LiX.LiF.ZhangL.WangB.et al (2016a)
313 (05), G505G10
Similarly, section 1833(t)(8)(F) of the Act requires under the OPPS that in the case of a Part B rebatable drug (except for a drug that has no copayment applied under subparagraph (E) of such section or for which payment is packaged into the payment for a covered OPD service or group of services), in lieu of the calculation of the copayment amount that would otherwise apply under the OPPS, the provisions of section 1847A(i)(5) of the Act shall, as determined appropriate by the Secretary, apply in the same manner as the provisions of section 1847A(i)(5) of the Act apply under that section
Keep in mind that natural products arent always suitable for everyone, and getting the dosage right is crucial