Sermorelin is sold as a nasal spray and as a troche as well as an injection, and the appeal is obvious: nobody likes needles. The question is whether the molecule survives the trip. For the nose, a handful of studies from the 1980s and 1990s give a measured answer. For the mouth, there is no answer at all.
How the injected form is dosed is covered in sermorelin dosage. This page covers the routes that skip the needle.
The approved form was an injection
Sermorelin is the first 29 amino acids of growth-hormone-releasing hormone, the brain signal that tells the pituitary to release growth hormone. It was sold in the United States as GEREF, and both approved GEREF products were injections [6].
One, approved in 1990, was a 0.05 mg ampule used to test whether the pituitary could release growth hormone. The other, approved in 1997, came in 0.5 mg and 1.0 mg vials to treat idiopathic growth hormone deficiency in children with growth failure [6].
The maker discontinued both in 2008. In 2013 the FDA determined they were not withdrawn for reasons of safety or effectiveness, which is why pharmacies can compound sermorelin today [6]. No nasal, oral or sublingual sermorelin has ever been approved.
Why a peptide struggles to cross the nose
A peptide like sermorelin is a chain of 29 amino acids, far larger than most drugs that are absorbed through the nose, and the lining of the nose is a barrier built to keep large molecules out. Whatever does get through still has to reach the pituitary at a concentration high enough to trigger a release. That is the theory; the studies below measure how much actually got through.
How much of a nasal dose reached the blood
3–5%
of a nasal GHRH(1-29) dose reached the blood in healthy men
Wilton 1993
~50×
the intravenous amount needed nasally for a similar growth hormone peak
Wilton 1993
7%
of intravenous effect once a surfactant was added to the spray
Pontiroli 1989
The clearest measurement comes from a Swedish study in 30 healthy men aged 19 to 43, which gave the same molecule either into a vein or into the nose [1]. Only 3% to 5% of the nasal dose reached the bloodstream.
Nasal sermorelin still worked, in the narrow sense of releasing growth hormone, and the response rose with the dose until it peaked at about 50 micrograms per kilogram [1]. That nasal dose was roughly as potent as 1 microgram per kilogram given intravenously.
The study also found that three nasal doses in one day did not suppress the body’s own growth hormone release the following night [1]. The authors thought the route worth testing in children with a specific form of growth hormone deficiency, but that is a suggestion, not a result.
An Italian study in six healthy men tried to fix the absorption problem [2]. It compared 50 micrograms of GHRH into a vein with 700 micrograms into the nose, with and without a surfactant called sodium glycocholate. Without it, nasal bioavailability was very low; with it, bioavailability rose to 7% of the intravenous effect.
A small study in children
A 1986 study blew 100 micrograms per kilogram into the noses of five children with short stature [3]. Growth hormone rose in all five, peaking at 15 minutes at an average of 28.3 ng/ml, and was still raised two hours later.
One child reported burning inside the nose, the only side effect recorded. The study measured a single dose, not growth over months, so it cannot say whether a nasal spray would treat anything.
What nasal GHRH did to sleep
The one study that connects the nasal route to sleep gave 300 micrograms of GHRH into the nose 30 minutes before bed, in a double-blind crossover of 12 young and 11 older men [4].
Nasal GHRH increased rapid-eye-movement sleep and slow-wave sleep, mostly in the second half of the night, and the effect did not depend on age [4]. It also lowered the cortisol low point at the start of sleep.
It also reduced the growth hormone rise that normally comes with early sleep, the opposite of what a reader buying a growth hormone peptide would expect. The authors read the results as a direct effect on the brain’s sleep regulation rather than on the pituitary, which is a hypothesis about mechanism, not a measured pathway. How sermorelin compares with other sleep peptides is in peptides for sleep.
Troches, tablets and oral sermorelin
PubMed indexes no human study of sermorelin taken by mouth, held under the tongue or dissolved as a troche. Swallowed peptides meet stomach acid and gut enzymes built to break proteins into amino acids, so any claim that an oral form raises growth hormone is, for now, untested rather than disproven.
What this means if you are choosing a form
The sermorelin trials that followed people for weeks or months used injections, so the evidence summarized in the sermorelin guide applies to the injected form. A nasal spray delivers a small, measured fraction of the dose to the blood, and an oral form has no human data at all.
For the results the injected trials reported, see does sermorelin work. The same absorption problem applies to other nasal products; the evidence for NAD+ is in NAD+ nasal spray. Several telehealth sellers list sermorelin; the Breeze Meds review sets out what one of them offers.
What the injected trials measured week by week, from 2 weeks to a year, is in sermorelin before and after. For sleep options with human studies, start at the sleep goal page.