GH axisFDA-approved useSubQ

HGH (Somatropin)

Also: Norditropin, Genotropin, Humatrope, Saizen, Omnitrope, Zomacton, Skytrofa (lonapegsomatropin), Ngenla (somatrogon)

Actual growth hormone in a vial. Sold as Norditropin, Genotropin, and others. The real thing, no triggering involved.

Typical dose

0.2 mg/day (~0.6 IU)

~4u, Daily

Cycle

Ongoing per FDA somatropin labels (Nord…

Timing

Pre-bed nightly (preferred) or fasted AM

Where

SubQ abdomen

Standard

FDA adult GHD

~4u

0.2 mg/day (~0.6 IU) · Daily

FDA somatropin label starting dose (non-weight-based), titrated to age/sex-adjusted IGF-1; well below the community ranges below. Pediatric GHD is weight-based.

Anti-aging

7–13u

1–2 IU/day · Daily pre-bed

Conservative anti-aging range. Gentle on insulin sensitivity. Good long-term starting point.

Body comp

13–27u

2–4 IU/day · Daily or split

Most commonly used body-composition dose. Expect water retention weeks 1–4 as tissues rehydrate, normal.

Advanced

27–40u

4–6+ IU/day · Split AM+PM

Higher performance dose. Insulin resistance and carpal tunnel become relevant, regular blood work important.

Off

Equal to on-time

Match off-time to on-time (3 mo on = 3 mo off) to preserve GH-receptor sensitivity.

Phase	How often	Dose	Units	Notes
FDA adult GHD	Daily	0.2 mg/day (~0.6 IU)	~4u	FDA somatropin label starting dose (non-weight-based), titrated to age/sex-adjusted IGF-1; well below the community ranges below. Pediatric GHD is weight-based.
Anti-aging	Daily pre-bed	1–2 IU/day	7–13u	Conservative anti-aging range. Gentle on insulin sensitivity. Good long-term starting point.
Body comp	Daily or split	2–4 IU/day	13–27u	Most commonly used body-composition dose. Expect water retention weeks 1–4 as tissues rehydrate, normal.
Advanced	Split AM+PM	4–6+ IU/day	27–40u	Higher performance dose. Insulin resistance and carpal tunnel become relevant, regular blood work important.
Off	Equal to on-time	–	–	Match off-time to on-time (3 mo on = 3 mo off) to preserve GH-receptor sensitivity.

Cycle & timing

Cycle: Ongoing per FDA somatropin labels (Norditropin, Genotropin, Humatrope, Saizen, Omnitrope, Zomacton) for adult/pediatric GHD; off-label anti-aging sometimes cycles 3–6 mo on / off (not FDA-labeled).

Timing: Pre-bed nightly (preferred) or fasted AM; no food 60–90 min before / 60 min after.

Where: SubQ abdomen. Never IM.

What to expect

Sleep and recovery improvement within 2–4 weeks. Body-composition changes over 3–6 months. Water retention common first 4–6 weeks. Joint comfort improves by week 6–8.

How much to buy

For 4-wk @ 4 iu × 7/wk:

× 10iu vials

× 12iu vials

× 15iu vials

× 24iu vials

Men & women

Men: Men convert GH to IGF-1 more efficiently and more often overshoot the age ceiling (a higher malignancy signal), aim mid-normal for age, don't chase the top.

Women: Women make ~3× the GH of men yet have similar IGF-1, they're less responsive, so often need a higher dose to move IGF-1. Oral estrogen blunts IGF-1 further (read it as running low); a skin patch/gel is more predictable.

Recommended mixes

Vial	Water	Strength
6 IU (2 mg)	0.4 mL	5 mg/mL
8 IU (2.67 mg)	0.53 mL	5 mg/mL
10 IU (3.33 mg)	0.67 mL	5 mg/mL
12 IU (4 mg)	0.8 mL	5 mg/mL
15 IU (5 mg)	1 mL	5 mg/mL
24 IU (8 mg)	1.6 mL	5 mg/mL

6 IU (2 mg): 1 unit = 0.05 mg

Storage

PowderFreeze-dried: 36–46°F (do NOT freeze).
MixedReconstituted: 36–46°F, up to 28 days with continuous refrigeration. Never freeze reconstituted.

Don't use if: Active malignancy · Acute critical illness (post-surgical, ICU): increased mortality reported in trials · Severe / proliferative diabetic retinopathy · Pregnancy and lactation

Stop if you notice

Severe headache with vision changes (rule out intracranial hypertension)
New-onset hyperglycemia
Persistent edema
New-onset hip pain in pediatrics

Side effects

Water retention, joint pain, carpal tunnel syndrome, insulin resistance.

Drug interactions

Glucocorticoids: blunt GH/IGF-1 response, reassess steroid dose. Insulin/antidiabetics: GH raises insulin needs, adjust. Levothyroxine: GH lowers free T4, recheck TSH/fT4 quarterly. Oral estrogens: blunt GH-stimulated IGF-1 (transdermal doesn't). CYP3A4 narrow-TI substrates (cyclosporine, tacrolimus, sirolimus): recheck troughs. Anticonvulsants (phenytoin, carbamazepine, phenobarbital): monitor levels.

Labs

IGF-1 (baseline + Week 8 + end; target ULN for age), Fasting glucose (Week 0/4/8) + HbA1c quarterly, Liver enzymes AST/ALT (baseline), Lipid panel (Week 0/12), TSH/fT4 quarterly, AM cortisol baseline (GH can mask central adrenal insufficiency), hip/scoliosis exam in pediatrics. Out of range? IGF-1 above your age range = too much growth signal (feeds hidden cancer, enlarges organs) → drop the dose; rising glucose/HbA1c = sugar creeping up.

What these labs mean →

Warnings

Boxed warning: do not use in acutely critically ill patients (post-surgical, ICU). Intracranial hypertension (papilledema, vision changes, headache, nausea, vomiting); surveillance required. Insulin resistance and new-onset T2DM; fluid retention, edema, carpal tunnel. IGF-1 elevation above age range carries theoretical malignancy risk; pancreatitis (rare). Pediatric: slipped capital femoral epiphysis; scoliosis progression.

Patient education

Vials must be refrigerated, never frozen (somatropin). Strict cold chain; never reuse. Rotate injection sites. Report headaches with nausea/vision changes immediately; report new joint pain. Children: report any limp or hip/knee pain immediately. Pen-device sharing prohibited even with a fresh needle (Norditropin, Genotropin, Humatrope, Saizen, Omnitrope, Zomacton are pen-delivered; cartridge contamination from prior puncture is documented).

These apply on top of the universal safety rules.

What it does

Recombinant human growth hormone, augments GH for body composition, recovery, anti-aging, and metabolic benefits. Binds GHR activating JAK2/STAT5 for IGF-1 production, protein synthesis, fat lipolysis, and cellular repair.

Long-acting weekly somatropins

Skytrofa (lonapegsomatropin), FDA-approved for adult GHD Jul 2025; Ngenla (somatrogon).

FDA label vs community dosing

Approach	Dose	Target
FDA, adult GH deficiency	0.15–0.3 mg/day (~0.45–0.9 IU), titrated	Restore IGF-1 to mid-normal for age, strictly replacement.
Community, recovery / anti-aging	1–2 IU/day (~0.33–0.67 mg), 5 days/wk	Above replacement; keep IGF-1 upper-normal, not above.
Bodybuilding, high-risk	4–8+ IU/day	Supraphysiologic, insulin resistance, edema, organ growth. Not endorsed.

Bottom line: the FDA dose is a titrated replacement to mid-normal IGF-1; community recovery doses run 2–4× that (upper-normal IGF-1); bodybuilding doses run far higher with real metabolic risk. Dose to your IGF-1, not to a fixed number.

References

peptidedosages DailyMed PubMed ClinicalTrials Drugs.com Span 2000 Weissberger 1991

From the guide, page 41–42.