Female:

Ovulation induction in infertility due to anovulation or impaired follicle‑ripening
Preparation of follicles for puncture in controlled ovarian hyperstimulation (ART)
Luteal phase support
Threatened and habitual abortion

Male:

Hypogonadotropic hypogonadism (including idiopathic dysspermias responsive to gonadotropins)
Delayed puberty due to insufficient pituitary gonadotropin function
Cryptorchidism (not due to anatomical obstruction)
Treatment of oligospermia

Highly purified HCG has LH activity, essential for gamete growth, maturation, and gonadal steroid production.
In females: substitutes the mid‑cycle LH surge to induce ovulation; supports luteal phase.
In males: stimulates Leydig cells to produce testosterone.
Plasma levels peak ~6 hours post injection; half‑life ~2 days; ~80% metabolized in kidneys.

Female (Ovulation induction/follicle preparation): Single injection 5000–10,000 IU after FSH treatment.
Luteal support: Two injections of 2500–5000 IU within 9 days post ovulation/embryo transfer.
Threatened/habitual abortion: 5000 IU deep IM twice weekly until 7th week of gestation.
Male (Hypogonadotropic hypogonadism): 2500–5000 IU twice weekly; add FSH if infertility is main complaint. Continue ≥3 months. Suspend testosterone replacement during therapy.

Known/suspected androgen‑dependent tumors (prostate, breast carcinoma in males).

Risk of multiple births after ovulation induction.
Risk of unwanted ovarian hyperstimulation (OHSS) with prior FSH treatment → monitor follicular growth and estradiol.
Avoid HCG if OHSS occurs.
Higher risk of ectopic pregnancy and pregnancy loss in ART.
In prepubertal boys: risk of precocious puberty or premature epiphyseal closure.