TestagenvsGonadorelin (GnRH)

Molecular Formula

C₁₇H₂₉N₅O₉

Molecular Weight

447.4 g/mol

Half-Life

Short plasma half-life typical of tetrapeptides (minutes to hours); biological effects persist for weeks to months through epigenetic modifications to testicular gene expression; metabolized to constituent amino acids

Bioavailability

Absorbed via intestinal peptide transporters (PepT1) in oral formulation; rapid absorption from subcutaneous injection sites; efficient cellular uptake and nuclear penetration due to short tetrapeptide structure

CAS Number

Not publicly registered

Molecular Formula

C₅₅H₇₅N₁₇O₁₃

Molecular Weight

1182.3

Half-Life

2-4 minutes

Bioavailability

Varies by route: ~5-20% (intranasal), 100% (IV/IM injections)

CAS Number

34973-08-5

Common

• Injection site reaction
• Mild fatigue
• Mild headache
• Libido fluctuation

Uncommon

• Mild acne or skin oiliness

Serious

• No documented serious adverse effects

Common

• Mild headache
• Local injection site reactions (redness, swelling)
• Temporary hot flashes
• Mood changes or emotional sensitivity
• Nausea or mild stomach upset
• Allergic skin reactions
• Dizziness or lightheadedness
• Temporary changes in vision
• Joint or muscle aches
• Insomnia or sleep disturbances
• Severe allergic reactions (difficulty breathing, swelling)
• Severe hormonal imbalance symptoms
• Ovarian hyperstimulation syndrome (OHSS)
• Signs of blood clots (chest pain, leg swelling)
• Severe mood changes or depression

Serious

• Severe allergic reaction

Evidence Level

Limited human trials

FDA Status

Research compound

Safety Overview

Testagen (lyophilized peptide complex) lacks published human safety data—all information derives from unpublished manufacturer data and theoretical extrapolation from rat studies. As an androgen secretagogue, it carries class risks including erythrocytosis (elevated red blood cell count), liver enzyme elevation, lipid profile unfavorable changes (reduced HDL, increased LDL), and prostate-related effects including urinary obstruction and potential malignancy acceleration. Cardiovascular risk including hypertension and increased thrombotic events are theoretical concerns based on androgen class pharmacology.

Contraindications

• xKnown hypersensitivity to peptide bioregulators or constituent amino acids (lysine, glutamic acid, aspartic acid, glycine)
• xHormone-sensitive cancers (prostate, testicular) — potential stimulation of androgen-dependent pathways
• xPregnancy and breastfeeding (female partners) — not applicable for direct use but consider reproductive implications
• xSevere hepatic or renal impairment — peptide metabolism may be altered

Evidence Level

Moderate human trials (Phase 1-2)

FDA Status

FDA approved for this use

Safety Overview

Gonadorelin is native GnRH and carries the safety profile established over 40+ years of clinical use in reproductive endocrinology. As the body's natural hormone, it produces minimal local side effects when dosed appropriately. The critical safety concern with gonadorelin is the initial flare effect within 24-48 hours of first dose—temporary elevation in FSH and LH—which can paradoxically suppress sex hormones before the desired stimulation occurs. This flare makes gonadorelin unsuitable for some conditions and explains why synthetic analogs (agonists, antagonists) are preferred in many modern fertility protocols.

Contraindications

• xPregnancy or breastfeeding
• xHormone-sensitive cancers (breast, prostate, ovarian)
• xSevere pituitary or hypothalamic disease
• xUndiagnosed abnormal vaginal bleeding
• xKnown hypersensitivity to GnRH