MEDICAL DISCLAIMER: Educational research guidelines only. Lyophilized peptides are investigational chemical compounds and are NOT approved for human consumption, diagnosis, or therapy. Consult a licensed physician before any research application.
Tabimorelin Dosage Chart, Schedule & Reconstitution Protocol
Quickstart Highlights
Tabimorelin (NN703) is an orally active, ipamorelin-derived ghrelin receptor (GHS-R1a) agonist that stimulates pulsatile growth hormone release and raises IGF-1 and IGFBP-3 [1][5]. Novo Nordisk developed it as a potential oral alternative to injected GH for growth-hormone-deficient adults. In trials it was dosed by mouth once daily at 0.05-12 mg/kg (single dose) and about 1.5-6.86 mg/kg/day over a week (PMID 11032702, 11437473). It worked as a biomarker tool — GH and IGF-1 rose dose-dependently — but failed clinically: only ~11% of GHD patients had a meaningful GH response, GH output declined with repeated dosing (tachyphylaxis), and it inhibited CYP3A4, raising midazolam exposure up to 93% (PMID 12699438, 12610745). Development was halted and it remains investigational, research-only, and unapproved. The subcutaneous reconstitution figures on this page are an educational measurement reference only — clinically the compound is swallowed, not injected — and are not medical advice.
Reconstitute: Add 2 mL bacteriostatic water → 10 mg/mL concentration.
Typical dose: 1.5-6 mg/kg/day oral (research only)
Easy measuring: At 10 mg/mL, 1 unit = 0.01 mL = 0.1 mg (100 mcg) on a U-100 insulin syringe.
Storage: Lyophilized powder: store at -20°C, protected from light. After reconstitution: refrigerate at 2-8°C and use within 2-4 weeks; do not freeze the reconstituted solution.
Half-life: ≈4.1 ± 0.4 hours after a single oral dose; lengthens with repeated dosing due to mechanism-based CYP3A4 autoinhibition.
Route: Oral once daily in all human trials; modeled here as a subcutaneous reconstitution reference for educational measurement only.
Status: Investigational; discontinued by Novo Nordisk; not approved by the FDA or EMA; research use only and banned in sport (WADA).
About Tabimorelin
Tabimorelin (NN703) is an orally active ghrelin / GHS-R1a agonist growth hormone secretagogue — a small, ipamorelin-derived molecule designed to be swallowed rather than injected [1][5]. In every published human trial it was given by mouth once daily as a weight-based dose; the subcutaneous reconstitution figures below are an educational measurement reference only, not the clinical route and not a recommended dose. Understanding the real Tabimorelin dosage means starting from the trial protocols: single oral doses of 0.05-12 mg/kg, and once-daily courses of about 1.5-6.86 mg/kg/day, which for a typical adult works out to roughly 100-840 mg per day [1][2][3].\n\nTo make the unit math measurable on a U-100 insulin syringe, this guide models a 20 mg vial reconstituted with 2.0 mL of bacteriostatic water (10 mg/mL, so 1 unit = 100 mcg). On that scale the illustrative reference points are 2.5 mg (25 units), 5 mg (50 units), and 10 mg (100 units) — deliberately far below the clinical oral milligram load, because injecting the true mg/kg amounts is neither practical nor advisable [1][2].\n\nFrequency: Once daily, matching the once-daily oral schedule used in all NN703 trials. Tabimorelin is investigational, was discontinued by Novo Nordisk, and is not approved by the FDA or EMA; this page is educational only and not medical advice.
Quick Protocol Navigation
Reconstitution Instruction & Mixing Step-by-Step
Lyophilized powder must be reconstituted carefully. Agitating peptide chains can shear disulfide bonds and render the peptide biologically inert.
Draw 2.0 mL of bacteriostatic water into a U-100 insulin syringe (or a larger luer syringe), enough to reconstitute one 20 mg Tabimorelin vial to a 10 mg/mL solution (1 unit = 100 mcg).
Swab the rubber stopper of the vial with an alcohol wipe, let it dry, then insert the needle through the center of the stopper.
Inject the water slowly down the inner glass wall of the vial; do not aim the stream directly at the powder and do not shake. Swirl gently until fully dissolved.
Let the vial rest for a few minutes; the solution should be clear and colorless. Discard it if it is cloudy or contains visible particulates.
Educational note: Tabimorelin is clinically taken ORALLY once daily — these subcutaneous reconstitution figures are a measurement reference only. For subcutaneous educational modeling, draw the target units, swab the site, inject slowly, and store the reconstituted vial refrigerated at 2-8°C.
Interactive Tabimorelin Syringe Calculator
Currently visualizing the 20 mg vial reconstituted with 2 mL bacteriostatic water. Adjust the target dose to dynamically render syringe units.
Reconstitution Calculation: 20mg dry powder in 2mL water yields 10.00 mg/mL. To evaluate a 250mcg dose, pull to 2.5 units (3 syringe ticks).
U-100 Syringe Representation
Educational reference visual. Assumes standard U-100 insulin syringe where 1.0 mL volume = 100 units.
Titration & Dose Escalation Schedules
| Phase | Dose per injection | Units (per injection) |
|---|---|---|
| Educational low reference (illustrative, not the clinical oral dose) | 2500 mcg (2.5 mg) | 25 units (0.25 mL) |
| Educational mid reference (illustrative, not the clinical oral dose) | 5000 mcg (5 mg) | 50 units (0.50 mL) |
| Educational upper reference (illustrative, not the clinical oral dose) | 10000 mcg (10 mg) | 100 units (1.00 mL) |
Administration guidelines: Refer to guidelines | 2 mL Reconstitution
Research Supplies Quantity Planner
Scientific mathematical planning of syringes, bacteriostatic water and dry vials needed for extended research blocks using the 20 mg vial.
Peptide Vials (Tabimorelin, 20 mg each):
- checkAt the ~5 mg/day mid educational reference (35 mg/week): about 14 vials over an 8-week course.
- checkAbout 21 vials over a 12-week course at the same reference dose.
- checkAbout 28 vials over a 16-week course; roughly half as many if modeling the 2.5 mg/day low reference.
- checkOrder a couple of spare vials to cover reconstitution loss and any wasted partial vials.
Insulin Syringes (U-100):
- checkOne injection per day (7 per week): about 56 syringes over 8 weeks.
- checkAbout 84 syringes over 12 weeks.
- checkAbout 112 syringes over 16 weeks; round up and keep spares for missed or fumbled draws.
- checkUse 0.5 mL (50-unit) syringes for the 25-100 unit illustrative reference range for easier reading.
Bacteriostatic Water (30 mL bottles): Use 2.0 mL per vial for reconstitution.
- check8-week course (~14 vials × 2.0 mL = ~28 mL): 1 bottle.
- check12-week course (~42 mL): 2 bottles.
- check16-week course (~56 mL): 2 bottles; store opened bottles refrigerated and observe their in-use expiry.
Alcohol Swabs: Use one to clean the vial stopper and one per injection site.
- checkAbout 2 swabs per day (vial stopper plus injection site): ~112 over 8 weeks.
- checkAbout 168 swabs over 12 weeks.
- checkAbout 224 swabs over 16 weeks; buy in boxes of 100-200 and keep extras on hand.
Mechanism of Action (MOA)
Tabimorelin (NN703) is a small, modified peptidomimetic — not a true peptide — that was rationally derived from the injectable growth-hormone-releasing peptide ipamorelin so that it could survive gastrointestinal degradation and reach the circulation after oral dosing [5][7]. It acts as a potent agonist of the growth hormone secretagogue receptor type 1a (GHS-R1a), the same G-protein-coupled receptor that binds endogenous ghrelin. By stimulating GHS-R1a on pituitary somatotrophs and on hypothalamic neurons, tabimorelin amplifies pulsatile growth hormone (GH) release, partly by potentiating GHRH signaling and blunting somatostatin tone [5]. The downstream effect is a rise in hepatic insulin-like growth factor 1 (IGF-1) and IGF-binding protein 3 (IGFBP-3). Because GHS-R1a activation is not perfectly GH-specific, tabimorelin also produced smaller, transient increases in ACTH, cortisol, and prolactin at higher doses [1].\n\nIn the original preclinical work, oral NN703 produced up to a 35-fold increase in peak GH in dogs with roughly 30% oral bioavailability, and it increased body-weight gain in rats over 14 days [5]. In healthy men, single oral doses from 0.05 to 12 mg/kg produced dose-dependent GH elevation, with statistically significant GH AUC increases at 3, 6, and 12 mg/kg and IGF-1 increases at 6 and 12 mg/kg [1].\n\nPharmacokinetics: after a single oral dose the plasma elimination half-life is approximately 4.1 ± 0.4 hours, which supports once-daily dosing [1]. A defining and ultimately problematic property is that tabimorelin is a mechanism-based ('suicide') inhibitor of CYP3A4 — the same enzyme that metabolizes it. With repeated daily dosing it inhibits its own clearance (autoinhibition), so exposure and effective half-life rise over time, and it markedly slows the clearance of other CYP3A4 substrates: co-administration raised midazolam AUC by 64% after one dose, 93% after 7 days, and still 45% after a washout period [4].\n\nA second limitation emerged on repeated dosing: GH responsiveness attenuated. In the 7-day study, GH release fell significantly from day 1 to day 7 despite continued dosing — a tachyphylaxis pattern — even as IGF-1 and IGFBP-3 stayed elevated [2]. In adults with growth hormone deficiency, a 1-week course (3 mg/kg on the first and last day, 1.5 mg/kg/day in between) produced a clinically meaningful peak GH response in only about 11% of patients, and serum IGF-1 was essentially unchanged after the week [3].\n\nTogether — modest efficacy in the target GHD population, tachyphylaxis, and the CYP3A4 drug-interaction liability — these findings led Novo Nordisk to halt development [3][4][6]. The real-world route is oral; the subcutaneous reconstitution scheme on this page is an educational measurement convention used across this site, not a clinically validated delivery method, and the figures shown are illustrative rather than a recommended dose.
Clinical Trial Efficacy Highlights
- starPreclinical characterization by Hansen and colleagues (1999, European Journal of Endocrinology) established NN703 as a novel orally active GH secretagogue derived from ipamorelin; oral dosing in dogs produced up to a 35-fold increase in peak GH with roughly 30% oral bioavailability, high GH specificity in swine, and increased body-weight gain in rats over 14 days [5].
- starIn a randomized, double-blind, placebo-controlled single-dose study in healthy men, Zdravkovic and colleagues (2000, Growth Hormone & IGF Research) tested eight escalating doses from 0.05 to 12 mg/kg; GH area-under-the-curve rose significantly at 3, 6, and 12 mg/kg and peak GH at the four highest doses, while IGF-1 increased significantly only at 6 and 12 mg/kg [1].
- starThe same group's 7-day once-daily study (2001, Growth Hormone & IGF Research) at 1.71, 3.0, 4.5, and 6.86 mg/kg showed dose-related GH AUC increases on days 1 and 7, but an overall significant decline in GH release from day 1 to day 7 (P<0.001), indicating tachyphylaxis, even though IGF-1 and IGFBP-3 remained elevated [2].
- starIn the pivotal patient trial, Svensson and colleagues (2003, Clinical Endocrinology) gave adults with growth hormone deficiency 3 mg/kg on the first and last day and 1.5 mg/kg/day in between for one week; only about 11% of patients achieved a peak GH response of at least 5 µg/L, and serum IGF-1 was unaffected, although IGFBP-3 rose [3].
- starA dedicated drug-interaction study (Zdravkovic et al., 2003, European Journal of Clinical Pharmacology) confirmed tabimorelin as a mechanism-based CYP3A4 inhibitor: co-administered midazolam AUC increased 64% after a single NN703 dose, 93% after 7 days of dosing, and remained 45% elevated after washout [4].
- starAfter a single oral dose the plasma half-life was about 4.1 ± 0.4 hours, but because the molecule inhibits its own CYP3A4-mediated metabolism, drug exposure and effective half-life increase with repeated daily dosing [1][4].
- starA 2020 review of growth hormone secretagogues (Ishida et al., JCSM Rapid Communications) places tabimorelin among orally active ghrelin-mimetic secretagogues whose biomarker effects did not translate into approvable clinical benefit, contextualizing why NN703 and similar agents were discontinued [6].
Side Effects & Tolerability Profile
Clinical subjects transiently report mild side effects. Slowly escalating the titration dose represents the single most effective intervention to limit side effects.
- warningGHS-R1a activation is not fully GH-specific: at doses above ~3 mg/kg, single-dose studies recorded transient individual increases in ACTH, cortisol, and prolactin, reflecting off-target pituitary stimulation [1].
- warningTabimorelin is a mechanism-based CYP3A4 inhibitor and raised exposure to the test substrate midazolam by up to 93%; in practice this means a high potential for serious interactions with the many drugs metabolized by CYP3A4 (statins, benzodiazepines, certain immunosuppressants, some antiarrhythmics, and others) [4].
- warningBecause it inhibits its own metabolism, repeated daily dosing can lead to drug accumulation and a progressively longer effective half-life, complicating dose titration [1][4].
- warningGH responsiveness diminished over a week of dosing (tachyphylaxis), so sustained efficacy was not maintained [2].
- warningAs a ghrelin-receptor agonist it would be expected to stimulate appetite and may cause gastrointestinal symptoms; sustained GH/IGF-1 elevation from GH secretagogues as a class is associated with fluid retention, peripheral edema, arthralgia, and reduced insulin sensitivity / higher fasting glucose.
- warningLong-term safety in humans is unknown: human exposure was limited to short phase I/II studies, and no chronic-use safety database exists.
- warningTabimorelin is investigational, was discontinued, and is not approved by the FDA, EMA, or any regulator; it is sold only as a research chemical, is not intended for human consumption, and is prohibited in sport under WADA's anti-doping rules.
- warningThe subcutaneous reconstitution model on this page is an educational measurement reference only; the clinical route is oral, and self-administration of a non-approved compound carries unquantified risks.
Subcutaneous Injection Technique
Most research peptides require subcutaneous injection into fatty tissue. Never inject directly into a blood vessel or deep muscle tissue unless clinically detailed.
1. Site Selection
Common locations include the abdomen (2 inches from navel), outer upper arms, or thighs.
2. Sanitization
Thoroughly clean the selected site, stopper and vial top using 70% isopropyl alcohol prep swabs.
3. Angle & Push
Pinch the skin and insert the needle at a 45 to 90-degree angle. Depress plunger smoothly.
4. Site Rotation
Rotate injection sites continuously to avoid lipodystrophy or tissue scarring.
Frequently Asked Questions
What is the typical Tabimorelin dosage?expand_more
There is no established therapeutic Tabimorelin dosage because the drug was never approved; all dosing comes from clinical trials. NN703 was given orally once daily: single doses of 0.05-12 mg/kg in healthy volunteers, multi-day courses of about 1.71-6.86 mg/kg/day, and an adult growth-hormone-deficiency protocol of 3 mg/kg on the first and last day with 1.5 mg/kg/day in between. For a 70 kg adult that is roughly 100-840 mg per day. These figures are historical research doses, not a recommendation; tabimorelin is for research use only.
Is Tabimorelin FDA approved?expand_more
No. Tabimorelin (NN703) was never approved by the FDA, the EMA, or any other regulator. Novo Nordisk advanced it through phase I/II trials in the early 2000s but discontinued development because efficacy in growth-hormone-deficient adults was modest, GH responses showed tachyphylaxis, and the molecule was a mechanism-based CYP3A4 inhibitor with significant drug-interaction potential. It is an investigational research chemical, not a medicine, and is prohibited in sport under WADA rules.
What is the half life of Tabimorelin?expand_more
After a single oral dose, tabimorelin's plasma elimination half-life is approximately 4.1 ± 0.4 hours, which supported once-daily dosing in trials. Importantly, because tabimorelin is a mechanism-based ('suicide') inhibitor of the CYP3A4 enzyme that clears it, the drug inhibits its own metabolism on repeated dosing, so exposure and the effective half-life increase over a multi-day course.
How is Tabimorelin reconstituted for an educational subcutaneous reference?expand_more
Clinically tabimorelin is swallowed, not injected, so reconstitution is only an educational measurement convention here. In this model a 20 mg vial is reconstituted with 2.0 mL of bacteriostatic water to give 10 mg/mL, where 1 insulin-syringe unit equals 100 mcg. Add the water slowly down the vial wall, swirl gently without shaking until clear, and refrigerate the solution at 2-8°C. The illustrative reference points (2.5, 5, and 10 mg) are deliberately far below the clinical oral milligram doses.
Can Tabimorelin be stacked with other compounds or drugs?expand_more
Caution is warranted. Tabimorelin is a potent mechanism-based CYP3A4 inhibitor — it raised exposure to the CYP3A4 substrate midazolam by up to 93% — so it can dangerously increase blood levels of the many medications cleared by CYP3A4, including some statins, benzodiazepines, immunosuppressants, and antiarrhythmics. Combined with its tachyphylaxis and lack of approval, this interaction profile is a key reason it is not used. Tabimorelin is research-only and not intended for human consumption or stacking.
Related Guides & Tools
Step-by-step references for reconstituting, measuring, and storing Tabimorelin, plus the universal dosing calculator.
Academic References & Study Citations
Zdravkovic M, Søgaard B, Ynddal L, 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. PMID 11032702. View Scientific Paper →
Zdravkovic M, Christiansen T, Eliot L, 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. PMID 11437473. View Scientific Paper →
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. PMID 12699438. View Scientific Paper →
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. doi:10.1007/s00228-002-0539-1. View Scientific Paper →
Hansen BS, Raun K, Nielsen KK, et al. Pharmacological characterisation of a new oral GH secretagogue, NN703. Eur J Endocrinol. 1999;141(2):180-189. PMID 10427162. View Scientific Paper →
Ishida J, Saitoh M, Ebner N, et al. Growth hormone secretagogues: history, mechanism of action, and clinical development. JCSM Rapid Commun. 2020;3(1):25-37. doi:10.1002/rco2.9. View Scientific Paper →
Tabimorelin (NN703), CID 9810101. PubChem, U.S. National Library of Medicine. CAS 193079-69-5; C32H40N4O3; MW 528.7. View Scientific Paper →
Tabimorelin. Wikipedia (overview of mechanism, development by Novo Nordisk, and discontinuation). View Scientific Paper →