Some of the approved drugs are synthetic versions of the natural hormones, such as trenbolone acetate and zeranol. Just like the natural hormone implants, before FDA approved these drugs, FDA required information and/or toxicological testing in laboratory animals to determine safe levels in the animal products that we eat (edible tissues). Furthermore, FDA required that the manufacturers demonstrate that the amount of hormone left in each edible tissue after treatment is below the appropriate safe level. As described above, a safe level is a level which would be expected to have no harmful effect in humans.
Unlike levonorgestrel, and like mifepristone , ulipristal acetate is embryotoxic in animal studies.  Before taking the drug, a pregnancy must be excluded.  The EMA proposed to avoid any allusion to a possible use as an abortifacient in the package insert to avert off-label use .  It is unlikely that ulipristal acetate could effectively be used as an abortifacient, since it is used in much lower doses (30 mg) than the roughly equipotent mifepristone (600 mg), and since mifepristone has to be combined with a prostaglandin for the induction of abortion.  However, data on embryotoxicity in humans are very limited, and it is not clear what the risk for an abortion or for teratogenicity (birth defects) is. Of the 29 women studied who became pregnant despite taking ulipristal acetate, 16 had induced abortions, six had spontaneous abortions, six continued the pregnancies, and one was lost to follow-up . 
• Many independent ranchers and farmers don’t use artificial hormones on their animals. By purchasing your milk and meat from local, sustainable farms, you are supporting a system that ensures the health and welfare of the farm animals, and protects you and your family from hormone-related health risks.
• Choose hormone-free beef and rBGH-free dairy products at the supermarket. Foods that carry the “USDA-certified organic” G label cannot come from animals given any artificial hormones. When purchasing sustainably raised foods without the "organic" label, be sure to check with the farmer to ensure no hormones were administered.