GHRP-6
In nine healthy men, GHRP-6 raised peak GH by 33.8 ± 4.8 µg/L from baseline (PMID 9543138; checked 24 Aug 2026). With a GHRH blocker first, the rise was 6.2 ± 1.8 µg/L (p < 0.0001). These human results belong to GHRP-6. They do not move to GHRP-6-Gly.
Which names and codes belong to GHRP-6?
GSRS shows Hexapeptide-2 and the sequence name His-D-Trp-Ala-Trp-D-Phe-Lys-NH2 (GSRS; checked 24 Aug 2026). It gives UNII 4H7N4I6X6A and CAS 87616-84-0.
GSRS also lists the development codes SKF-110679, SK&F-110679, and U-75799E (checked 24 Aug 2026). The live register also has the spellings GHRP6 and GHRP 6.
GHRP-6-Gly adds one glycine at the start and is a different compound. Its lab evidence stays separate.
What did the randomized nine-person study measure?
Nine healthy men attended two study visits (PMID 9543138; checked 24 Aug 2026). They got GHRP-6 after saline or after a GHRH blocker.
| GH measure | Without antagonist | With antagonist | Comparison |
|---|---|---|---|
| Peak rise from baseline | 33.8 ± 4.8 µg/L | 6.2 ± 1.8 µg/L | p < 0.0001 |
| Area under the curve | 1,701 ± 278 µg/min × L | 376 ± 113 µg/min × L | p < 0.001 |
The blocker removed most of the GH response. PubMed marks US government support from PHS and non-PHS sources. It names no agency or grant. Funding in the full paper was not checked.
What did the nine-person Phase I study find?
Nine healthy men received one intravenous administration at three test levels (PMID 23099431; checked 24 Aug 2026).
| Pharmacokinetic result | Measured value | Primary source |
|---|---|---|
| Distribution half-life | 7.6 ± 1.9 minutes | PMID 23099431 |
| Elimination half-life | 2.5 ± 1.1 hours | PMID 23099431 |
| Atypical elimination-phase concentration spikes | 4 of 9 participants | PMID 23099431 |
Blood exposure tended to rise in line with the test level. PubMed lists no grant. Funding in the full paper was not checked.
What larger combined study is available?
PMID 12201831 studied 146 adults with pituitary disease and 203 healthy adults (349 total; checked 24 Aug 2026). The test used both GHRH and GHRP-6. It does not show what GHRP-6 did by itself.
The 30-minute GH value correlated with the peak at r = 0.994 (p < 0.0001). Using one value changed the classification for 5 of 203 controls and 2 of 146 patients.
The abstract calls the combined test safe and reliable. It gives no count or table of adverse events. PubMed lists no grant. Funding in the full paper was not checked.
What safety details do the records provide?
None of the three abstracts has a full adverse-event table (checked 24 Aug 2026). The Phase I abstract records unusual blood-level spikes in four people. It does not call them adverse events.
These papers give no long-term results. An exact-name ClinicalTrials.gov search found no registered study.
What does evidence tier B mean here?
A controlled human study measured the GH response. A Phase I study measured its movement through blood. Tier B stays right for GHRP-6 (checked 24 Aug 2026).
The tier does not transfer to GHRP-6-Gly.
What does the US FDA orphan record show?
The FDA gave the sequence orphan status for growth failure in children on 23 May 1990 (FDA orphan record 46190; checked 24 Aug 2026). The sponsor was SmithKline Beecham Pharmaceuticals.
The record status is Designated/Designation Withdrawn or Revoked. The FDA record says Not FDA Approved for Orphan Indication.
What is the recorded EU status?
The EU Commission index has no exact entry for GHRP-6 or Hexapeptide-2 (Union Register index; checked 24 Aug 2026). The EU field stays unclear.
Why is the first-observed field 2011-02?
PMID 21298258 came out online on 6 February 2011 (checked 24 Aug 2026). The doping-control paper names GHRP-6 among drug candidates targeted for urine testing. It says their misuse remained unrecognized.
This supports 2011-02 as the paper date for a current misuse target. It is not a product seizure or sale date.
What does this register entry cover?
This entry covers the identity of GHRP-6 and selected human studies. It does not cover GHRP-6-Gly.
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