A plain explanation of IGF-1, what 'HGH releaser' supplements are made of, and what the evidence says. That includes the single published GenF20 Plus trial, whose main result was not significant.
Start with what these products are not: they're not growth hormone. "HGH supplements" are blends of amino acids and herbs, marketed as a way to get your body to release more of its own. Doctors judge growth hormone activity through a blood marker called IGF-1 (insulin-like growth factor 1). Evidence for the supplements is weak. Mayo Clinic says research does not show that they raise HGH, and the one published GenF20 Plus trial saw no significant IGF-1 rise against placebo across all participants.
Your pituitary gland releases human growth hormone (HGH) in bursts, and much of that happens while you sleep. The hormone prompts the liver to make IGF-1, which then carries out many of its effects. HGH swings widely over a day, which is why blood tests use IGF-1 instead, as it's the steadier of the two.
Most HGH boosters and releasers are built from amino acids, including L-arginine, L-glutamine, L-ornithine and GABA. Many add herbs (Tribulus, astragalus) or animal extracts (deer antler velvet, colostrum). Arginine did raise growth hormone in studies, but those used several grams. Products in this category usually contain far less. GenF20 Plus lists 130 mg of L-arginine per serving; HyperGH 14x lists 520 mg a day. Back in 2005 the FTC stated it knew of no competent evidence that HGH pills or sprays raise growth hormone.
GenF20 Plus is among the few products that can point to a published placebo-controlled trial (2015, 61 adults completing 12 weeks). On GenF20 Plus, IGF-1 climbed more than on placebo, but across all participants that gap wasn't statistically significant. The one significant finding came from a post hoc analysis of people aged 40 and over. Growth hormone itself was not measured. Body fat, lean mass, energy, sleep and libido looked no different from placebo. HyperGH 14x, which is aimed at people who train, has no published trial of its own.
Both L-arginine and GABA can lower blood pressure. Arginine also interacts with nitrates, ED drugs, blood pressure medicines and diabetes medicines. If you have had cancer, have diabetes or are pregnant, check with your doctor before using any product sold to raise growth hormone or IGF-1. Prescription growth hormone is something else altogether. Our piece on HGH supplements vs HGH injections covers the difference.