In mice, two synthetic growth‑hormone‑releasing‑hormone (GHRH) compounds – an antagonist (MIA‑690) and an agonist (MR‑409) – reduced brain inflammation and oxidative stress, and produced anxiety‑reducing and antidepressant‑like behaviours. Both drugs also raised brain norepinephrine and serotonin levels. The antagonist was a bit more powerful at cutting inflammatory markers, while the agonist lowered the brain’s own GHRH‑receptor after weeks of use.
Casanueva. F F FF; Borras. C G CG; Burguera. B B; Lima. L L; Muruais. C C; Tresguerres. J A JA; Deve...
Giving a short burst of growth‑hormone‑releasing hormone (like sermorelin) makes the pituitary release a normal amount of growth hormone even in women with anorexia who have very low estrogen, and the same is true when estrogen receptors are blocked with tamoxifen. Prolactin also rises a little right after the injection but then falls back to baseline.
Peticlerc. D D; Pelletier. G G; Lapierre. H H; Gaudreau. P P; Couture. Y Y; Dubreuil. P P; Morisset....
In this animal study, two versions of a human growth‑hormone‑releasing peptide—one short (1‑29, like sermorelin) and one longer (1‑44)—were given to young cows and pigs at several doses. Both peptides caused the same amount of growth‑hormone release, with no significant differences in peak levels or overall exposure, although the highest dose gave a two‑phase spike in cows and the pig response was more erratic. The results suggest the shorter peptide works just as well as the longer one for boosting GH, but the findings are from livestock, not people.
In a small study of kids with low growth hormone, giving the natural hormone-releasing peptide (GHRH) helped some grow, but the standard growth‑hormone shots worked better. The longer‑acting peptide (GHRH‑1‑40) given in short nightly bursts was more effective than the shorter version (GHRH‑1‑29) taken twice a day, unless the dose of the short version was doubled.
In rats, giving the growth‑hormone‑releasing peptide (like sermorelin) causes a quick GH spike, but males and females react differently to repeated shots. Female rats keep responding even when the peptide is given often, while male rats only respond every few doses and then become temporarily unresponsive. This suggests that dosing frequency and sex affect how the body reacts to GRF‑based peptides.
Rafferty. B B; Poole. S S; Clarke. R R; Schulster. D D
The study shows that sermorelin (a growth‑hormone‑releasing factor) disappears from the blood very quickly and only a tiny amount (about 4%) gets into the bloodstream when injected under the skin, likely because it breaks down fast at the injection site.
The study shows that a synthetic 29‑amino‑acid version of growth‑hormone‑releasing factor (sermorelin) can quickly raise human growth hormone levels, reaching about 40 ng/mL in healthy volunteers and peaking within an hour in children, though kids with true GH deficiency respond less. It also finds few false‑positive results, suggesting the peptide could help diagnose GH problems. For DIY health enthusiasts, this confirms that a single dose can give a short‑term GH boost, but it won’t fix a real deficiency and long‑term safety isn’t covered.
The study shows that short IV doses of two growth‑hormone‑releasing‑hormone (GHRH) peptides, including sermorelin (GHRH‑1‑29‑NH2) and a slightly modified version (D‑Ala2), cause a quick rise in growth hormone in healthy men, with the modified peptide being about twice as strong. No other hormones were changed and only mild flushing was seen at the highest dose.
Grossman. A A; Lytras. N N; Savage. M O MO; Wass. J A JA; Coy. D H DH; Rees. L H LH; Jones. A E AE;...
This old study shows that the short version of growth‑hormone‑releasing factor (the peptide in sermorelin) works just as well as the longer natural form at raising growth hormone levels, both in healthy people and in patients who lost GH after brain radiation. It also suggests the short peptide can be used to test how much GH the pituitary can release. For DIY health enthusiasts, it confirms that a single 200 µg dose of sermorelin can give a measurable GH spike, but the data are from a tiny group and not a new breakthrough.
Dubreuil. P P; Pelletier. G G; Petitclerc. D D; Lapierre. H H; Couture. Y Y; Brazeau. P P; Gaudreau....
In growing pigs, both the natural levels of growth hormone (GH) and the boost you get from a GH‑releasing factor (like sermorelin) get smaller as the animals get older. The boost also depends a lot on when you give the factor – it works best if you inject it right after a low‑GH period or just before a natural GH spike, and not during a high‑GH period.
Heiman. M L ML; Nekola. M V MV; Murphy. W A WA; Lance. V A VA; Coy. D H DH
This study shows that the GH‑releasing peptide (like sermorelin) works at unbelievably low concentrations in a rat pituitary cell test, and that tiny changes to its building blocks can make it much stronger or much weaker. While it doesn’t give direct human dosing advice, it tells biohackers that the peptide is extremely potent and that small tweaks matter a lot.
Kopelman. P G PG; Noonan. K K; Goulton. R R; Forrest. A J AJ
In obese women, the body doesn’t release as much growth hormone (GH) when given a hormone‑like peptide that normally triggers GH (like sermorelin), and this blunted response is even worse in those who also have a weak prolactin reaction to low‑blood‑sugar tests. This suggests that excess weight can mess up the brain‑pituitary signals that control GH.
Looij. B J BJ; Nieuwenhuijzen Kruseman. A C AC; Mudde. A H AH; Frölich. M M; Piaditis. G P GP;...
The study shows that a short piece of growth hormone‑releasing hormone (the same thing in sermorelin) reliably spikes growth hormone levels, causes a tiny, short‑lived bump in prolactin, and makes the thyroid‑stimulating hormone (TSH) response bigger when it’s given together with other hypothalamic hormones like TRH. In other words, sermorelin does what it’s supposed to (boost GH) and can also boost TSH under certain conditions.
Tauber. M T MT; Pienkowski. C C; Landier. F F; Gunnarsson. R R; Rochiccioli. P P
In a small study of short children with low growth hormone, a continuous skin infusion of a GHRH peptide (the same kind of molecule as sermorelin) boosted their GH levels, especially at a higher dose (40 µg/kg/day). However, the boost got smaller after three weeks, hinting that the body may adapt to the constant exposure. The findings suggest that intermittent dosing or longer‑acting versions might work better.
Genazzani. A D AD; Petraglia. F F; Gastaldi. M M; Gamba. O O; Corazza. F F; D'Ambrogio. G G; Genazza...
In women who stopped menstruating because they lost weight, a GH‑releasing hormone test (like sermorelin) caused a bigger GH surge than in healthy women, but their IGF‑1 levels stayed low, showing the GH system is out of balance when body weight is low.
Siejka. A A; Ławnicka. H H; Komorowski. J J; Stepień. T T; Krupiński. R R; Stepie&...
In a lab test, the natural hormone that tells the pituitary to release growth hormone (GHRH) made immune cells release more of the signaling molecule IFN‑gamma, while a drug that blocks GHRH did the opposite. This shows GHRH can directly affect immune activity, at least in a dish.
Scientists made modified versions of the growth‑hormone‑releasing peptide (GRF‑29) by adding small alkyl groups. In rats, some of these tweaks made the peptide up to 100‑times more powerful at boosting GH and kept it active much longer, probably because the changes protect it from being broken down. The work shows how chemistry can dramatically improve the drug‑like properties of GH‑releasing peptides, but the compounds aren’t sold commercially and safety in people isn’t known yet.
Fernandez-Gonzalez. M A MA; Barrios. V V; Sancho. J I JI; Arilla. E E; Carmena. M J MJ; Tresguerres....
When you inject the growth‑hormone‑releasing factor analogue (sermorelin) into rats, it shows up in the blood quickly if given IV, but more slowly if given under the skin or into the belly. The peptide breaks down fast, and it mainly ends up in the gut and the pituitary gland, not in the thyroid or parathyroid.
Sato. M M; Chihara. K K; Kita. T T; Kashio. Y Y; Okimura. Y Y; Kitajima. N N; Fujita. T T
The study shows that when growth hormone (GH) spikes, it triggers a rise in somatostatin that then suppresses the next GH pulse. This feedback loop happens during the low‑point (trough) of the natural GH rhythm. Blocking somatostatin stops this suppression, meaning the timing of GH‑boosting agents matters.
Blacklay. A A; Grossman. A A; Ross. R J RJ; Savage. M O MO; Davies. P S PS; Plowman. P N PN; Coy. D...
The study shows that a synthetic version of the hormone that tells the pituitary to release growth hormone (GHRH, also known as sermorelin) can still trigger growth hormone spikes in kids whose brains were irradiated and who have growth hormone deficiency. This suggests the problem is a lack of the brain's signal, not a broken pituitary, and that giving the synthetic signal can work as a treatment.