How It Works

Pregnyl works by mimicking LH, the hormone normally released by the pituitary gland.

Normal pathway:

1. Hypothalamus releases GnRH

2. Pituitary releases LH and FSH

3. LH stimulates testicular Leydig cells

4. Testes produce testosterone and sperm

When LH is suppressed (TRT, steroids, pituitary issues), the testes stop producing testosterone and shrink.

hCG bypasses this shutdown by directly stimulating the testes, restoring testosterone production even when LH is low.

Effects in men:

• stimulates testosterone production

• restores testicular size

• supports sperm production

How to Use It

Dosage

Common medical dosing varies widely depending on goal:

Fertility protocols

• 1,500–3,000 IU

• 2–3× per week

Testicular function during TRT

• 250–500 IU

• 2–3× per week

Restarting testes after suppression

• 1,000–2,000 IU

• 3× per week

(Protocols vary depending on physician and hormone status.)

Frequency

Usually injected:

• 2–3 times per week

because hCG remains active roughly 36–48 hours in the body after injection.

Cycle Length

Depends on purpose:

Sperm production takes about 70–90 days, so fertility protocols often require several months.

Stacking

Pregnyl is commonly used with:

• FSH injections (for fertility)

• Clomiphene or Enclomiphene

• Testosterone therapy

• Aromatase inhibitors (if estrogen rises)

FSH is often added when sperm production needs stronger stimulation.

Post-Cycle Therapy (PCT)

Pregnyl is often used in PCT because anabolic steroids suppress the hypothalamic-pituitary-gonadal axis (HPG axis).

Typical role in PCT:

1. hCG reactivates the testes

2. SERMs (Clomid/Nolvadex) restart LH production from the brain

Without LH stimulation, testes remain inactive.