Side-by-side · Research reference

SermorelinvsTestagen

Side-by-side comparison across mechanism, dosage, evidence, side effects, administration, and stack synergies. Citations on every claim where available.

APhase 3HUMAN-REVIEWED14/43 cited

BAnimal-MechanisticHUMAN-REVIEWED11/41 cited

Sermorelin

GHRH 1-29 fragment · Short-acting

100–500 mcgPer doseMolteno 2013

Phase 3Evidence levelWalker 1994 Molteno 2013

~12 minHalf-lifeMolteno 2013

SQ · Pre-sleep · 1×/day

Testagen

Bioregulator Peptide · Khavinson School

Lys-Glu-Asp-GlySequenceFedoreyeva 2011

NuclearLocalizationFedoreyeva 2011

TesticularTissue target

SQ · Abdomen · Cyclical

01Mechanism of Action

Parameter

Sermorelin

Testagen

Primary target

Pituitary GHRH receptorWalker 1994

Testicular tissue; proposed nuclear DNA interaction

Pathway

GHRH-R → Gαs → cAMP → PKA → GH vesicle exocytosisWalker 1994

Nuclear penetration → DNA/oligonucleotide binding → gene expression modulation (bioregulator hypothesis)Fedoreyeva 2011

Downstream effect

Pulsatile GH release; subsequent IGF-1 elevationMolteno 2013

Proposed support for spermatogenesis and testicular function; mechanistic data limited to nuclear localization and DNA interactionFedoreyeva 2011

Feedback intact?

Yes — short pulse preserves feedback

Unknown — no HPG axis data

Origin

Unmodified active 29-AA fragment of human GHRH (1-44)Walker 1994

Khavinson bioregulator school — isolated from testicular tissue peptide fractions

Antibody development

—

02Dosage Protocols

Parameter

Sermorelin

Testagen

Standard dose

100–500 mcg per injectionMolteno 2013

—

Frequency

Once daily, pre-sleep

Once daily or alternate days

Lower / starter dose

100 mcg per dose

—

Evidence basis

Phase 3 (Geref pediatric); clinical practiceWalker 1994 Molteno 2013

Animal mechanistic / in vitro onlyFedoreyeva 2011

Duration

8–12 weeks per cycle

—

Reconstitution

Bacteriostatic water

Sterile water or bacteriostatic saline

Timing

Pre-sleep, fasted preferred

—

Half-life

~12 min (plasma)Molteno 2013

Shorter than tesamorelin (~26 min) — simpler GHRH analogue.

Unknown — likely minutes (short peptide)

Typical protocol (anecdotal)

—

100–200 mcg / day

No published human dosing studies; derived from Russian bioregulator practice.

Cycle length

—

10–20 days on, 10–14 days off

Bioregulator tradition uses pulsed cycles; no controlled data.

Route

—

Subcutaneous

04Side Effects & Safety

Parameter

Sermorelin

Testagen

Injection site reaction

Mild erythema, transient pain

—

Flushing / headache

Common transient effect

—

IGF-1 elevation

Modest at standard doses

—

Cancer risk

Contraindicated in active malignancy (GH/IGF-1 axis)

—

Pregnancy / OB

Avoid

—

Glucose handling

Generally neutral

—

Injection site reactions

—

Erythema, mild irritation (potential)

Systemic effects

—

Unknown — no human safety data

Hormonal impact

—

No published data on testosterone, LH, FSH effects

Long-term safety

—

Unknown — no long-term studies

Absolute Contraindications

Sermorelin

·Active malignancy
·Pregnancy / breastfeeding
·Disrupted hypothalamic-pituitary axis

Testagen

·Active testicular malignancy

Relative Contraindications

Sermorelin

·Untreated diabetes

Testagen

·Hormone-sensitive cancers (no data; theoretical caution)
·Pregnant or breastfeeding (no data)

05Administration Protocol

Parameter

Sermorelin

Testagen

1. Reconstitution

Add 2 mL bacteriostatic water to 5 mg vial → 2.5 mg/mL = 250 mcg per 0.1 mL.

Add 1–2 mL sterile or bacteriostatic water to lyophilised vial. Swirl gently; do not shake. Solution should be clear.

2. Injection site

SQ — abdomen or thigh. Rotate sites.

Subcutaneous — abdomen or thigh. Rotate sites daily. Use standard insulin syringe (27–31G).

3. Timing

Pre-sleep, fasted.

Morning or evening; no established optimal timing. Anecdotal preference: evening to align with circadian testosterone patterns.

4. Storage

Lyophilised: room temp, light-protected. Reconstituted: refrigerate ≤30 days.

Lyophilised: room temp, dark. Reconstituted: refrigerate 2–8 °C, use within 14–21 days if bacteriostatic water used.

5. Needle

29–31G, 4–8 mm insulin syringe.

10–20 days on, 10–14 days off. Bioregulator tradition uses pulsed exposure; rationale: prevent receptor/pathway desensitisation.

06Stack Synergy

Sermorelin

+ Ipamorelin

Strong

View Ipamorelin →

Sermorelin (GHRH analogue) and ipamorelin (selective GHRP) form the prototypical GHRH+GHRP dual-axis stack at the lowest cost. Both peak within 30 min and produce a sharp physiological GH pulse without cortisol/prolactin elevation.

Sermorelin: 200–300 mcg SQ · pre-sleep
Ipamorelin: 200–300 mcg SQ · same injection
Primary benefit: Pulsatile GH stimulation, recovery, body composition

Raun 1998 Walker 1994

Testagen

— no documented stacks