Growth Hormone

Tabimorelin

NN703 · NNC 26-0161

Tabimorelin stands as a massively potent, orally active Growth Hormone Secretagogue (GHS) that pushed deep into Phase II clinical trials for severe adult GH deficiency. Operating as a highly engineered, true peptide-mimetic, it successfully breached the gastric barrier without requiring injection. While ultimately shelved by pharma in favor of highly profitable recombinant HGH, it remains a testament to elite secretagogue engineering designed to maximize natural pulsatile release.

Not FDA-approved - research chemical
Reviewed by CalcMyPeptide Editorial Team
Last updated: August 2026Evidence: Low
Typical research dose
0.5-10 mg/day (oral)
Frequency
1× daily (oral)
Half-life
~3 hours
Common vials
N/A (oral)
CAS
193079-69-5
Molecular weight
557.7 g/mol

Use-case scores

0–10 against the evidence we have, not a gym ranking. Hidden domains do not apply here.

  • Muscle / recomp3/10

    Historical oral ghrelin-mimetic program. Not MK-677. Not a living obesity NDA.

Compound card

Class
Oral GHS-R1a agonist (NN703 class; not ibutamoren)
Formula
C32H39N5O4
Status
Not FDA-approved · research use

How it works

Tabimorelin (NN703) is a synthetic, orally active non-peptide growth hormone secretagogue (GHS). Like Ibutamoren (MK-677), it was designed to mimic ghrelin and bind to the ghrelin receptor (GHS-R1a) to stimulate a powerful, pulsatile release of naturally occurring human growth hormone (HGH) and IGF-1 from the pituitary gland.

It was developed as a potential oral treatment for age-related growth hormone deficiency (somatopause) and frailty. While it effectively raises IGF-1 levels, it holds lower affinity than MK-677 and development was largely paused in clinical trial phases.

Source: PMID: 11401563

Background & History

Tabimorelin (NN703) was developed by Novo Nordisk as a potential oral alternative to GH injections for growth hormone deficient adults. It entered Phase II clinical trials in the early 2000s showing dose-dependent GH elevation, but the magnitude of IGF-1 increase and clinical endpoints were modest compared to established GH replacement therapy. Development was discontinued, but tabimorelin remains an important reference compound in the growth hormone secretagogue field.

Research Use Cases

  • ✓GH deficiency research
  • ✓Oral GH secretagogue development
  • ✓GHS-R1a pharmacology research

Dosing

PhaseDoseFrequencyNotes
Research / Clinical TrialsOral capsuleDailyAbandoned in clinical trials. Replaced functionally in research/market by the more potent Ibutamoren (MK-677).

Administration

Route / form
Oral
Timing
N/A
Empty stomach?
No - Food timing is not critical.

Timeline

Acute
Stimulates large pulse of systemic HGH and IGF-1.

Who it is for

Growth Hormone Secretagogue

Low

Historical interest; essentially a lesser-known, discontinued analogue conceptually identical to MK-677.

Safety & Considerations

Not FDA approved. Like all ghrelin mimetics, likely induces severe hunger and temporary insulin resistance.

Regulatory & Legal Status

FDA Status (US)
Research Only
WADA Status (2026)
Not Listed

Not currently on the WADA 2026 Prohibited List. Policies may change - verify before competition.

Classification

Research Chemical

US Compounding: Not eligible / not available

⚠️ This information is for educational purposes only and may not reflect the most current regulatory updates. Always verify with official FDA, WADA, and jurisdiction-specific sources before use.

Limits of current evidence

  • Not interchangeable with MK-677.

Verdict

Tabimorelin is an older oral GH secretagogue. Do not treat it as ibutamoren. Development history is not a 2026 pharmacy SKU.

Interactions & Contraindications

May increase cortisol and prolactin transiently. Similar drug interaction profile to other ghrelin mimetics - caution with insulin-sensitizing agents due to potential GH-mediated insulin resistance.

Synergies & Common Stacks

Both are oral GHS-R1a agonists. MK-677 is a non-peptide while tabimorelin is a peptide-mimetic - useful for comparing structural class effects on GH secretion patterns.

Tabimorelin and GHRP-2 share the GHS-R1a mechanism. Comparing oral (tabimorelin) vs injectable (GHRP-2) routes.

Frequently Asked Questions

Is Tabimorelin a peptide?▼
No, like MK-677, it is a non-peptide chemical developed to mimic a peptide (ghrelin) while maintaining high oral bioavailability.

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