Human chorionic gonadotropin

ID: hcg

Aliases: hCG, HCG

Type: compound

Route/form: subcutaneous or intramuscular injection

Status: approved

Evidence level: approved / labelled

Best data tier: approved label + human controlled/review

Support scope: human, review/regulatory

Source types: human_rct, human_trial, label, review

Linked sources: 6

Broad outcomes: Hormones / fertility / sexual health, PEDs / AAS / thermogenics

Reading note: These are curation notes anchored to linked sources, not a clinical recommendation or protocol.

Targets / mechanism

• LH receptor agonist

Optimization domains

• fertility
• testosterone
• endocrine
• on cycle support
• pct discussions

Research basis

• Optimization angle: during exogenous androgen suppression, hCG is relevant because it supplies LH-like testicular signaling rather than trying to stimulate the pituitary.
• Human suppression-model data show low-dose hCG can maintain or dose-dependently raise intratesticular testosterone, which is the strongest mechanistic reason it appears in fertility and testicular-volume discussions.
• Short-course and fertility-recovery literature place hCG beside clomiphene in selected male hypogonadism or AAS-suppression contexts, but the endpoint is testicular function/fertility rather than direct anabolism.

Limits, risks, and missing evidence

• This is not automatically enough to keep serum testosterone, fertility, libido, neurosteroids, or performance in a target range; serum T, intratesticular T, sperm output, and symptoms are different endpoints.
• hCG can raise estradiol and does not restore hypothalamic-pituitary signaling; it is a direct gonadal signal, not a full HPTA reset.
• Use during or after AAS/TRT requires lab and fertility context; it should not be presented as making an androgen cycle low-risk.

Risk flags

• prescription only
• endocrine axis
• estradiol increase
• fertility context
• medical supervision

Linked papers, labels, and reviews

1. DailyMed label: Pregnyl chorionic gonadotropin for injection
   label / dailymed_pregnyl_label
   Official chorionic gonadotropin label; anchors indication, contraindication, ovarian hyperstimulation, thromboembolism, precocious puberty, and supervision cautions.
2. Low-dose hCG maintains intratesticular testosterone in normal men with testosterone-induced gonadotropin suppression
   human_rct / pubmed_hcg_intratesticular_2005
   Mechanistically important for TRT-plus-hCG fertility discussions.
3. Clomiphene citrate and hCG are both effective in restoring testosterone in hypogonadism
   human_rct / pubmed_clomiphene_male_hypogonadism_rct_2018
   Short-course randomized male hypogonadism study.
4. Endotext: Hypogonadotropic hypogonadism and gonadotropin therapy
   review / ncbi_endotext_hh_gonadotropin_therapy
   Clinical review explaining pulsatile GnRH versus gonadotropin therapy and fertility endpoints.
5. Dose-dependent increase in intratesticular testosterone by very low-dose human chorionic gonadotropin in normal men with experimental gonadotropin deficiency
   human_rct / pubmed_hcg_dose_dependent_itt_2010
   Controlled human model showing dose-dependent intratesticular testosterone response to very-low-dose hCG under experimental gonadotropin deficiency.
6. Fertility outcomes in men with prior history of anabolic steroid use
   human_trial / pubmed_aas_prior_use_fertility_hcg_clomiphene_2023
   Human fertility-recovery cohort using discontinuation plus clomiphene/hCG regimen; relevant to AAS-induced suppression discussions, not proof of safe cycling.