Peptide Comparison
NafarelinvsHuman Chorionic Gonadotropin (HCG)
A potent GnRH agonist that initially stimulates then suppresses reproductive hormones, used for treating endometriosis and central precocious puberty with convenient nasal spray delivery.
A powerful hormone that mimics luteinizing hormone (LH) to stimulate your body's natural testosterone production while keeping your fertility intact—like having your cake and eating it too for men on hormone therapy.
At a Glance
Quick
comparison
Dose Range
Nafarelin
As prescribed–As prescribed mg
Human Chorionic Gonadotropin (HCG)
250–2000 IU
Frequency
Nafarelin
Once daily
Human Chorionic Gonadotropin (HCG)
Twice weekly
Administration
Nafarelin
As directed by healthcare provider
Human Chorionic Gonadotropin (HCG)
Subcutaneous injection
Cycle Length
Nafarelin
Ongoing/indefinite
Human Chorionic Gonadotropin (HCG)
Ongoing/indefinite
Onset Speed
Nafarelin
Moderate (1-2 weeks)
Human Chorionic Gonadotropin (HCG)
Moderate (1-2 weeks)
Evidence Level
Nafarelin
Strong human trials (Phase 3 or FDA approved)
Human Chorionic Gonadotropin (HCG)
Strong human trials (Phase 3 or FDA approved)
Efficacy
Benefit
ratings
Endometriosis Treatment
Precocious Puberty
Hormone Regulation
Fertility Preservation
Testicular Health
Hormone Balance
Technical Data
Compound
specifications
Nafarelin
Molecular Formula
C66H83N17O13
Molecular Weight
1322.5 g/mol
Half-Life
Approximately 2-6 hours (varies by route of administration)
Bioavailability
~2-3% (intranasal)
CAS Number
86220-42-0
Human Chorionic Gonadotropin (HCG)
Molecular Formula
C1105H1770N318O336S26 (approximate)
Molecular Weight
36,700 g/mol (approximately)
Half-Life
24-36 hours
Bioavailability
High when injected subcutaneously or intramuscularly
CAS Number
9002-61-3
Protocols
Dosing
tiers
Nafarelin
Human Chorionic Gonadotropin (HCG)
Applications
Best
suited for
Nafarelin
Managing moderate to severe endometriosis pain that doesn't respond to other treatments
Nafarelin is particularly well-suited for individuals focused on managing moderate to severe endometriosis pain that doesn't respond to other treatments. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Treating children with precocious puberty (early puberty)
Nafarelin is particularly well-suited for individuals focused on treating children with precocious puberty (early puberty). Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Preparing women for endometriosis surgery by reducing inflammation
Nafarelin is particularly well-suited for individuals focused on preparing women for endometriosis surgery by reducing inflammation. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Improving fertility outcomes in assisted reproductive procedures
Nafarelin is particularly well-suited for individuals focused on improving fertility outcomes in assisted reproductive procedures. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Human Chorionic Gonadotropin (HCG)
Fertility Preservation During TRT
If you're on testosterone therapy but want to keep your swimmers swimming, HCG is your best friend. It keeps your testes active and producing sperm even when external testosterone would normally shut that down. Research shows it can maintain or restore spermatogenesis in about 80% of men.
Preventing Testicular Atrophy
Nobody wants their boys to shrink. When you take external testosterone, your brain stops signaling your testes to work—and they get smaller from disuse. HCG mimics the signal (LH) that keeps them active, maintaining their size and function.
Hypogonadotropic Hypogonadism
If your pituitary gland isn't sending the right signals to your testes (low LH), HCG can step in and do the job. It's been used for decades to treat this condition, helping men achieve normal testosterone levels and fertility.
Post-Cycle Therapy (PCT)
After using anabolic steroids, your natural hormone production is suppressed. HCG can help jumpstart your testes back into action, speeding up the recovery of your natural testosterone production. It's often used as part of a comprehensive PCT protocol.
Safety Profile
Side
effects
Nafarelin
Common
- Hot flashes and night sweats (happen in 90% of users)
- Mood changes including depression or anxiety
- Decreased sexual interest
- Vaginal dryness
- Headaches
- Nasal irritation (if using spray formulation)
- Breast tenderness
- Muscle aches and joint pain
- Weight gain or changes in body composition
- Nausea and upset stomach
- Sleep problems
- Emotional sensitivity and mood swings
- Allergic reactions (rare)
- Significant bone density loss with extended use
- Severe mood disorders requiring medical attention
- Hot flashes (flushes of heat and redness)
- Night sweats and chills
- Vaginal dryness and discomfort
- Mood depression or anxiety
- Changes in sexual desire
- Weight changes
- Headaches
- Muscle and joint aches
- Nasal irritation or sinus problems
- Breast tenderness or swelling
- Acne
- Sleep disturbances
- Nausea
- Fatigue
- Bone pain
Serious
- Severe allergic reaction
Human Chorionic Gonadotropin (HCG)
Common
- Injection site reactions
- Headache
- Water retention
Uncommon
- Gynecomastia
- Mood changes
- Acne
Serious
- Blood clots
Research Status
Safety
& evidence
Nafarelin
Evidence Level
Strong human trials (Phase 3 or FDA approved)
FDA Status
FDA approved for this use
Safety Overview
Nafarelin is FDA-approved with a well-established safety profile across decades of clinical use for endometriosis and precocious puberty. The most significant safety consideration is hypogonadism and bone density loss during prolonged therapy, requiring add-back therapy (norethindrone 0.4 mg daily) after 6 months to prevent osteoporosis. Common side effects—hot flashes, vaginal dryness, mood changes—are reversible upon discontinuation and typically diminish with continued use.
Contraindications
- xPregnancy (can harm fetus - must use non-hormonal birth control)
- xHypersensitivity to GnRH agonists
- xUndiagnosed vaginal bleeding
- xSevere osteoporosis or bone disease
Human Chorionic Gonadotropin (HCG)
Evidence Level
Strong human trials (Phase 3 or FDA approved)
FDA Status
FDA approved for other use
Safety Overview
HCG has been used medically for over 80 years with a well-established safety profile. When used appropriately for male hypogonadism or fertility preservation, side effects are generally mild and manageable. The most common issues relate to elevated estrogen from increased testosterone aromatization, which can be managed with aromatase inhibitors if needed. Serious side effects are rare when HCG is used under medical supervision.
Contraindications
- xHormone-sensitive cancers (prostate, breast)
- xPrecocious puberty in children
- xKnown allergy to HCG or any component
- xPregnancy (in therapeutic male contexts)
- xUntreated thyroid or adrenal disorders
Decision Guide
Which is
right for you?
Choose Nafarelin if...
- Managing moderate to severe endometriosis pain that doesn't respond to other treatments
- Treating children with precocious puberty (early puberty)
- Preparing women for endometriosis surgery by reducing inflammation
- Improving fertility outcomes in assisted reproductive procedures
Choose Human Chorionic Gonadotropin (HCG) if...
- Fertility preservation during TRT
- Maintaining testicular size and function
- Natural testosterone stimulation
- Post-cycle therapy recovery