Tabimorelin
Also called NN703, NN-703 and NNC-26-07031
Tabimorelin is a growth hormone pill that Novo Nordisk tested around 2000 and then dropped. It is a small, peptide-like molecule that acts like the hunger hormone ghrelin to release growth hormone, and it works by mouth.1, 2, 11 In healthy men it raised growth hormone, but the effect was smaller after a week of daily doses.4 In 97 adults with growth hormone deficiency, a week of it left IGF-1 unchanged, and only 1 in 9 who took it had a clear growth hormone response.5 It also blocks CYP3A4, a liver enzyme that clears many common drugs: in 17 healthy men it nearly doubled blood levels of midazolam, a sedative cleared by that enzyme.6 It was never approved, and there is no legal way to buy it.
It works much like MK-677, another oral growth hormone booster. See the peptide regulatory tracker for how they compare legally.
In this guide
At a glance
| What it is | An oral growth hormone secretagogue: a small molecule built from two modified amino acids and an amino-hexenoyl cap1, 11 |
|---|---|
| Taken | By mouth, in every human study3, 4, 5 |
| Best evidence | A randomized trial in 97 adults with growth hormone deficiency, lasting about a week. Most didn't respond5 |
| Development | Discontinued by Novo Nordisk. No date or reason published2 |
| No human evidence for | Muscle, fat loss, sleep, recovery or anti-aging |
| Main risks | Drug interactions through CYP3A4. Short rises in stress and other pituitary hormones. No long-term safety data4, 6, 7 |
| Legal status | Not approved. No legal route for pharmacy compounding. Not in the 2026 HHS peptide policy9, 10 |
| In sport | Banned at all times (WADA S2.2.4)11 |
| Typical cost | No legal source to price |
Where to get it
MoveWell sells nothing and earns nothing from this page. There is no legal way to buy tabimorelin. Why
Never approved, not in any approved drug and not on FDA's compounding list. The 2026 HHS peptide policy doesn't cover it.9, 10
WhyDevelopment was discontinued. We found no trial since the early 2000s.2
The studiesMolecular structure
A small molecule, about the size of MK-677. Two modified amino acids, a naphthyl-alanine and a phenylalanine, both N-methylated and in the D form, carry an amino-hexenoyl cap that isn't an amino acid.
The 5-amino-5-methylhex-2-enoyl cap
- Type
- Small peptide-like molecule, taken by mouth
- Formula
- C32H40N4O3
- Weight
- 528.7 g/mol
- PubChem
- CID 9810101
- CAS
- 193079-69-5
- Target
- Ghrelin receptor (growth hormone secretagogue receptor)
Drawn from the structure listed for PubChem CID 9810101; formula and weight computed from it and matching published values.1, 7
What it is
Novo Nordisk developed tabimorelin, code-named NN703, as a pill to treat growth hormone deficiency.2 Its chemical name describes two modified amino acids, N-methyl-D-naphthylalanine and N-methyl-D-phenylalanine, joined to an amino-hexenoyl cap.1 That makes it peptide-like, but small enough to work by mouth.3
WADA classes it with the growth hormone secretagogues and their mimetics, the same group as MK-677, ipamorelin and the hunger hormone ghrelin.11
Human studies were published from 2000 to 2003. A drug-development database lists its status as discontinued, with no date or reason given.2, 3, 5
How it works
- Growth hormone release. Single oral doses raised growth hormone in healthy men at the higher doses, and IGF-1 rose at the two highest.3
- Fading effect. Taken daily for 7 days, it still raised growth hormone, but less on day 7 than on day 1.4
- Other hormones. On the first day, prolactin, TSH and ACTH rose at some doses. The TSH and ACTH rises didn't follow the dose.4
- Liver enzyme. Lab tests found it is a long-acting (mechanism-based) inhibitor of CYP3A4, an enzyme that breaks down many prescription drugs. In people, midazolam levels rose 64% after one dose and 93% after a week, and were still 45% higher a week after stopping.6
Evidence map
Each claimed use is graded separately. A grade measures how much evidence exists, not whether the result was good news.
Two small randomized studies, single doses and 7 days. A lab number, and the response was smaller after a week
One randomized trial of 97 people for about a week. IGF-1 unchanged, most didn't respond
No study found. User reports only
Scale: 5 FDA-approved, 4 strong human, 3 limited human, 2 animal or lab only, 1 anecdotal
Key studies
| Use | Study | Model | Finding |
|---|---|---|---|
| Healthy men | Zdravkovic 20003 | Human RCT 8 dose levels | Single doses. Growth hormone up at the higher doses, IGF-1 up at the two highest. No significant rise in stress or other pituitary hormones overall. Well tolerated |
| Healthy men | Zdravkovic 20014 | Human RCT 4 doses, 7 days | Growth hormone up on days 1 and 7, but less on day 7. IGF-1 up at the three highest doses |
| GH deficiency | Svensson 20035 | Human RCT n=97 adults | About a week. After a week, growth hormone no different from placebo. 9 of 83 (11%) reached a clear response. IGF-1 unchanged. Generally well tolerated |
| Drug interaction | Zdravkovic 20036 | Human, open-label n=17 healthy men | Midazolam, a drug cleared by CYP3A4: exposure up 64% after one tabimorelin dose and 93% after 7 days, still 45% up a week after stopping |
The authors of the deficiency trial concluded most adults with growth hormone deficiency did not respond, and suggested it might help only some with moderately severe deficiency.5
By goal
Pick your goal to see what the evidence supports.
| Goal | Human evidence | Result |
|---|---|---|
| Muscle or fat loss | None found | Unknown |
| Growth hormone deficiency | One RCT, n=97, about a week | IGF-1 unchanged. Most didn't respond |
| Raising growth hormone | Two small RCTs in healthy men | Yes, but less by day 7 |
How it's used
No dose is approved for any use, and we don't give one. In the studies it was a pill given under medical supervision, for one day up to about a week, with doses set by body weight.3, 4, 5 No study tested longer use.
Side effects and who should avoid it
- Drug interactions. It blocks CYP3A4. In healthy men a week of tabimorelin nearly doubled levels of midazolam, a drug cleared by that enzyme, and the effect lasted past a week off it.6 Many common drugs are cleared the same way, so their levels could rise too.
- Pituitary hormones. Prolactin, TSH and ACTH rose on the first day at some doses in healthy men. By day 7, ACTH and cortisol were lower than on placebo at some doses.4
- Short studies only. The longest study lasted about a week. Nothing is known about longer use.4, 5
- Related drugs. FDA lists MK-677, which works the same way, among compounding ingredients with significant safety risks.8 Tabimorelin was never studied long enough to know its risks. See our MK-677 guide.
- Unknown products. Anything sold online is a research chemical, outside FDA's drug quality rules.12
- Athletes. Banned at all times.11
Compared with
| Tabimorelin | MK-677 | |
|---|---|---|
| Taken | By mouth | By mouth |
| Target | Ghrelin receptor | Ghrelin receptor |
| Development | Discontinued | In a phase 3 trial in children, as LUM-201 |
| Longest human study | About a week | Up to 2 years |
| FDA compounding | Not reviewed; no legal route | Category 2; advisers voted 1–13 against |
| In sport | Banned, S2.2.4 | Banned, S2.2.4 |
Sources: AdisInsight,2 FDA Category 2 list,8 advisory committee minutes,13 WADA 2026 list.11 MK-677 trial details are referenced in our MK-677 guide. See also ipamorelin, an injected ghrelin-receptor agonist.
Stacks
We found no study of tabimorelin with any other compound. Pairing it with other growth hormone boosters such as ipamorelin, hexarelin or sermorelin has never been tested, and its effect on CYP3A4 adds an interaction risk with other drugs.6
Myths vs evidence
All options
MoveWell sells nothing and has no commercial link on this page. Checked November 1, 2026
| Route | Status | Why |
|---|---|---|
| Prescription drug | None | Never approved; development discontinued2 |
| Compounding pharmacy | No legal route | Not in an FDA-approved drug and not on FDA's 503A bulks list. Not in the HHS policy9, 10 |
| Telehealth | None found | Superpower, which offers compounded peptides, doesn't list it14 |
| Clinical trial | None | Development discontinued2 |
Research chemical sellers
We don't list sellers. In August 2026 FDA warned five peptide sellers that a "research use only" label doesn't excuse products clearly meant for people.12
Legal status history
Newest first.
- Current statusNever approved; development discontinued. No legal route for pharmacy compounding. Not covered by the HHS peptide policy. Banned in sport.2, 9, 10, 11
- Nothing scheduled that we found.
- HHS enforcement discretion policy covers six peptides. Tabimorelin is not one of them.10
- WADA's 2026 list names tabimorelin under S2.2.4, banned at all times.11
- FDA's compounding advisers vote 1–13 against MK-677, a related oral secretagogue. Tabimorelin was never reviewed.13
- Latest update in a drug-development database lists tabimorelin as discontinued.2
- Trial in adults with growth hormone deficiency published; most didn't respond.5
- First human study in healthy men published.3
FAQ
Is tabimorelin legal?
It was never approved, pharmacies have no legal route to make it, and it isn't in the 2026 HHS peptide policy. Products sold online are research chemicals, not legal for people.
Is it a peptide?
It's peptide-like: two modified amino acids plus a non-amino-acid cap. It's small enough to work as a pill.
Why was it dropped?
No reason has been published. The trial in adults with growth hormone deficiency found most didn't respond.
Does it build muscle?
No study measured muscle or strength.
What dose do people use?
No dose is approved for any use. We don't give one.
Can athletes use it?
No. WADA bans tabimorelin at all times under S2.2.4.
Is it like MK-677?
Yes, in how it works: both are oral drugs that act on the ghrelin receptor. MK-677 has longer trials and is still in development as LUM-201. Tabimorelin was dropped.
References
14 sources, with links
- DrugMAP (IDRB). Tabimorelin (DMNL9HO): synonyms, structure, PubChem CID 9810101, CAS 193079-69-5. Link
- AdisInsight. Tabimorelin drug profile: originator Novo Nordisk; status discontinued (somatotropin deficiency); latest update Jan 21, 2011. Link
- Zdravkovic M, et al. The pharmacokinetics, pharmacodynamics, safety and tolerability of a single dose of NN703, a novel orally active growth hormone secretagogue in healthy male volunteers. Growth Horm IGF Res 2000;10(4):193–198. Index record
- Zdravkovic M, et al. The pharmacokinetics, pharmacodynamics, safety and tolerability following 7 days daily oral treatment with NN703 in healthy male subjects. Growth Horm IGF Res 2001;11(1):41–48. Index record
- Svensson J, Monson JP, Vetter T, et al. Oral administration of the growth hormone secretagogue NN703 in adult patients with growth hormone deficiency. Clin Endocrinol (Oxf) 2003;58(5):572–580. DOI 10.1046/j.1365-2265.2003.01754.x
- Zdravkovic M, Olsen AK, Christiansen T, et al. A clinical study investigating the pharmacokinetic interaction between NN703 (tabimorelin), a potential inhibitor of CYP3A4 activity, and midazolam, a CYP3A4 substrate. Eur J Clin Pharmacol 2003;58(10):683–688. PMID 12610745
- Wikipedia. Tabimorelin (checked Nov 1, 2026). Link
- FDA. Certain bulk drug substances for use in compounding that may present significant safety risks (Category 2 includes ibutamoren mesylate; tabimorelin not listed; current as of Apr 22, 2026). fda.gov
- FDA. Bulk drug substances used in compounding under section 503A of the FD&C Act (updated May 14, 2026). fda.gov
- HHS. 503A peptide enforcement discretion policy, Appendix B (Oct 28, 2026). hhs.gov
- World Anti-Doping Agency. 2026 Prohibited List, S2.2.4 growth hormone releasing factors (copy hosted by SEGAS). PDF
- ArentFox Schiff. RUO-ined: five peptide vendors learn research use only is not a legal strategy (Sep 18, 2026; on FDA warning letters of Aug 24, 2026). Link
- FDA. Final summary minutes of the Pharmacy Compounding Advisory Committee meeting, Oct 29, 2024. fda.gov
- Superpower. Peptides page (checked Nov 1, 2026; tabimorelin not listed). Link
This page is for education and is not medical advice. Tabimorelin is not approved for any use. Talk to a clinician before taking anything that changes your hormones.