If you read the fine print there is usually a note that there is no growth hormone but rather a growth hormone promoter.Which is supposed too make your body produce more of its own growth hormone.
These are things too set growth hormone apart.

*it can either be real 191 amino acid sequence(somatropin) or it can be 192 amino acid sequence(somatrem) which is actually growth hormone mimic...with potentially nasty side effects.
*it can be pure high quality hgh(comes at a higher price) or it can be cheaply produced and contain bacterial residue left over from the manufacturing process.
*it can be bought through a doctor's prescription(high price) or it can be bought on the black market(in which case you need to be extra careful as most of the brands are counterfeit containing hgh of questionable origin if it's real at all). If buying from a non reputable source you should have lab blood work done to confirm authenticity.
*it can be produced in the U.S.A./E.U.(comes at an absurdly high price due to Big Pharma monopoly of the western markets) OR it can be produced in Asia(China, Korea, India etc.) In which case there is quality/purity differences from brand to brand.
*it can be in liquid form(very fragile, sensitive to room temperature and shaking) or it can be lyophilized freeze dried powder form(suitable for shipping world wide. Never buy liquid form on the black market because there is no way to know how it was handled before it gets to you.
*it can be authentic(contains what it claims) or it can be counterfeit. In which case scammers relabel vials of questionable origin. And make then look original then offer them at a too good to be true price. To lure in the victims.
*various brands come at valid dosed vials. The dosage/strength per vial can be 4iu,10iu,12iu,40iu. Which doesn't matter as long as the price per iu is right.
SO WHICH HGH IS THE BEST
High quality:
GENOTROPIN(191 amino acid, high purity, produced by Pfizer inc(USA)
HUMATROPE(191 amino acid, high purity, produced by Eli Lilly and company(USA)
HYPERTROPIN(191 amino acid, high purity, produced by Neogenica Bioscience Ltd (China)
JINTROPIN(191 amino acid, high purity, produced by Genescience Pharmaceutical co. Ltd.(China)
NORDITROPIN(191 amino acid, high purity, produced by Novo Nordisk Inc.(USA)
NUTROPIN(191 amino acid, high purity, produced by Genetech USA Inc.(USA)
SAIZEN(191 Amino acid, high purity, produced by EMD Serono Inc. (USA)
SEROSTIM(191 amino acid, high purity, produced by EMD Serono Inc. (USA)
ZORBTIVE(191 amino acid, high purity, produced by EMD Serono Inc. (USA)
Medium quality:
ANSOMONE(used to be 192 but is now 191 amino acid, medium quality, produced by Anhui Anke Biotechnology co. Ltd).(China)
HYGETROPIN(191 amino acid, medium purity, produced by Zhongshan Hygene Biopharm co. Ltd).(China)
TEV TROPIN(191 amino acid, medium purity, produced by Teva pharmaceuticals),(USA)
ZOMACTON(191 amino acid, medium purity, produced by Ferring pharmaceutical pty Ltd). (Australia)
Low or questionable quality
FITROPIN(this product has been discontinued it was produced by Shenzhen Lexington biotech co. Ltd). (China)
GETROPIN(relabeled from an unknown origin)
GLOTROPIN(unlabeled from an unknown origin)
KEFEI(191 amino acid, low purity, produced by Shangai United Kefei biotechnology co. Ltd).(China)
KIGTROPIN(relabeled of unknown or questionable origin, known to cause immune response, different reviews from basic to batch.)
RIPTROPIN(relabeled of unknown origin, mostly present on the UK black market, different reviews from batch to batch.)
TAITROPIN(labeled of unknown origin, presumably associated with Kigtropin.)
Found at somatropin.cn