HMG (with Bacteriostatic Water)

Human Menopausal Gonadotropin (HMG, sometimes "human menopausal gonadotrophin" or menotrophin) is a combined gonadotropin preparation containing approximately equal activity of follicle-stimulating hormone (FSH) and luteinizing hormone (LH), historically purified from the urine of postmenopausal women in whom both gonadotropins are markedly elevated due to the loss of ovarian negative feedback on the hypothalamic-pituitary-gonadal (HPG) axis. The first clinical HMG preparation, Pergonal, was developed in the 1960s by Bruno Lunenfeld and Piero Donini at the Istituto Farmacologico Serono and represents one of the foundational preparations in modern reproductive endocrinology.

This research-supply preparation provides HMG as a lyophilized powder reconstituted with bacteriostatic water. HMG is one of the standard reproductive-endocrinology research preparations used in studies of HPG-axis function, gonadal steroidogenesis, follicular development, and Leydig-cell function. The standard activity unit for gonadotropin preparations is the International Unit (IU); HMG preparations are typically labeled by IU of FSH activity with the LH activity in approximately equivalent proportion.

This page is a research-only educational reference. The preparation is supplied as a research-supply product for laboratory and research-supply use and is not intended for human consumption or any therapeutic application. No medical claims are made on this page.

HMG is a heterogeneous gonadotropin preparation containing FSH and LH in approximately equal biological activity. The two component gonadotropins are heterodimeric glycoproteins consisting of a common α-subunit (shared with thyroid-stimulating hormone TSH and human chorionic gonadotropin hCG) and a hormone-specific β-subunit that confers receptor specificity. FSH (~30-35 kDa, depending on glycosylation) binds the FSH receptor (FSHR) on granulosa cells of the ovary and Sertoli cells of the testis. LH (~28-32 kDa) binds the LH/CG receptor (LHCGR) on theca cells of the ovary, Leydig cells of the testis, and luteal cells.

The historical HMG preparations are derived from the urine of postmenopausal women — a context in which loss of ovarian estrogen and inhibin negative feedback on the hypothalamus and pituitary produces sustained elevation of pituitary FSH and LH secretion, with substantial gonadotropin excretion in urine. The original Pergonal product and subsequent generations of urinary HMG preparations were purified from large pools of postmenopausal urine through ion-exchange and other purification steps. Modern HMG preparations (e.g., Menopur) typically include additional purification steps and may include exogenous hCG to standardize the LH activity (since hCG and LH both bind LHCGR with similar affinity and exogenous hCG is a more reproducible source of LH-like activity than the endogenous LH retained in urinary preparations).

Recombinant FSH (Gonal-F, Follistim) and recombinant LH (Luveris) were developed in the 1990s-2000s as alternatives to urinary preparations, providing single-component gonadotropin activity with higher specific activity and elimination of urine-source contaminants. The choice between HMG and recombinant preparations in clinical reproductive medicine is a matter of clinical-protocol and cost considerations; in the research-supply context, HMG provides a combined FSH/LH activity preparation that is well-characterized in the published reproductive-endocrinology literature.

The HPG axis was characterized through the early-to-mid 20th century with the identification of pituitary FSH and LH as the principal hormonal regulators of gonadal function. The recognition that postmenopausal women excrete substantial gonadotropin activity in urine — initially characterized by Selmar Aschheim and Bernhard Zondek in pregnancy-urine experiments and extended to postmenopausal urine by subsequent investigators — provided the source material for the development of clinical gonadotropin preparations.

Bruno Lunenfeld and Piero Donini at the Istituto Farmacologico Serono in Rome developed the first clinical HMG preparation in the late 1950s and early 1960s, with Pergonal (the trade name registered by Serono) entering clinical use in 1962. The development required collection of large volumes of postmenopausal urine, which in the historical Pergonal program was sourced from convents and women's religious communities in Italy and elsewhere — a logistical detail that became part of the cultural history of reproductive medicine. Carlo Lunenfeld's clinical work in the 1960s established HMG as a foundational tool for treatment of anovulatory infertility and for the controlled ovarian stimulation that supports modern assisted reproductive technology (ART).

Robert Edwards and Patrick Steptoe developed in-vitro fertilization in the 1970s using HMG-based ovarian stimulation, leading to the birth of Louise Brown in 1978 (the first IVF birth) and ultimately the 2010 Nobel Prize in Physiology or Medicine to Edwards. The development of ART protocols substantially expanded the clinical use of gonadotropin preparations through the 1980s-1990s.

Recombinant gonadotropin preparations entered clinical use in the 1990s: recombinant FSH (Gonal-F, Serono, 1996; Follistim/Puregon, Organon, 1996) and recombinant LH (Luveris, Serono, 2000). Modern HMG preparations have been refined for higher purity and reproducible activity standards (e.g., Menopur, Ferring, 2005). The research-supply context includes both urinary-source HMG preparations and recombinant single-component preparations, with HMG representing the combined FSH/LH research-context tool with the deepest historical literature.

The hypothalamic-pituitary-gonadal (HPG) axis is the central neuroendocrine pathway regulating reproductive function in both sexes. Gonadotropin-releasing hormone (GnRH), a decapeptide secreted from the hypothalamic preoptic and arcuate nuclei in a pulsatile pattern, binds GnRH receptors on anterior pituitary gonadotrope cells and stimulates the synthesis and pulsatile release of FSH and LH. The two gonadotropins reach gonadal tissues through the systemic circulation and act on receptor-bearing target cells to regulate gametogenesis and gonadal steroidogenesis.

In the ovary, FSH acts on granulosa cells of developing follicles to support follicular growth, granulosa-cell proliferation, and aromatase expression (which converts androgen substrates to estrogen). LH acts on theca cells to support androgen substrate synthesis (the "two-cell two-gonadotropin" model of ovarian estrogen synthesis: theca-LH-androgen and granulosa-FSH-aromatase-estrogen) and on preovulatory follicles to trigger ovulation and luteinization of the residual follicular cells into the corpus luteum.

In the testis, FSH acts on Sertoli cells of the seminiferous tubules to support spermatogenesis (the multi-week process of germ-cell development from spermatogonia to mature spermatozoa) and to regulate inhibin B secretion (which provides negative feedback to pituitary FSH). LH acts on Leydig cells of the testicular interstitium to support testosterone biosynthesis from cholesterol precursor.

Negative feedback on the HPG axis is provided by gonadal steroids (estrogen, testosterone, progesterone) acting at hypothalamic and pituitary sites, and by gonadal peptides (inhibin A and B, activin, follistatin) acting principally at the pituitary on FSH synthesis. In the postmenopausal context, loss of ovarian estrogen and inhibin negative feedback produces sustained elevation of pituitary FSH and LH secretion — the biochemical basis for HMG as a urinary-source gonadotropin preparation.

The principal research applications of HMG and gonadotropin preparations in reproductive endocrinology center on this HPG axis. Controlled ovarian stimulation protocols use exogenous FSH (with or without LH) to recruit multiple follicles for assisted reproductive procedures. Sertoli-cell and Leydig-cell research uses FSH and LH respectively to characterize tissue-specific gonadotropin responses. HPG-axis suppression and reactivation research uses gonadotropin preparations to characterize the axis's response to perturbation. Models of polycystic ovarian syndrome (PCOS), hypothalamic amenorrhea, and other reproductive-endocrine conditions use gonadotropin preparations as research-context tools.

In the research-supply context, HMG is used as a combined-activity preparation in studies that require both FSH and LH activity, while recombinant single-component preparations are used when isolated FSH or LH activity is required. The choice depends on the specific research question.

HMG is a mixture of two heterodimeric glycoprotein hormones, FSH and LH, in approximately equal biological activity. Each gonadotropin consists of two non-covalently associated subunits: a common α-subunit (~14 kDa, 92 amino acids in the mature protein, shared with TSH and hCG) and a hormone-specific β-subunit (~14-18 kDa, 111 amino acids for FSHβ and 121 amino acids for LHβ) that confers receptor specificity. The mature heterodimers are 28-35 kDa depending on the specific glycosylation pattern and on which gonadotropin is considered.

Both gonadotropins are heavily glycosylated, with N-linked oligosaccharide chains on multiple sites in both subunits. The glycosylation pattern affects circulating half-life (more heavily sialylated isoforms have longer half-lives due to reduced hepatic clearance by the asialoglycoprotein receptor), receptor binding kinetics, and biological potency. Urinary HMG preparations contain a mixture of glycoforms reflecting the in-vivo glycosylation patterns produced by the pituitary gonadotropes.

The standard activity unit for gonadotropin preparations is the International Unit (IU), defined by the World Health Organization international reference standard for the relevant gonadotropin. HMG preparations are typically labeled by IU of FSH activity (75 IU FSH being a standard ampoule strength), with the LH activity in approximately equivalent proportion. The IU is a biological-activity unit (defined by bioassay), not a mass unit, and the mass-to-IU conversion depends on the specific glycoform composition.

For research-supply HMG, the relevant specifications appear on the supplier's certificate of analysis: activity (IU per vial), purity (limits on extraneous urinary proteins), sterility (for parenteral research formats), and pH after reconstitution. The lyophilized format provides good stability at appropriate storage conditions (typically refrigerated, with -20°C for long-term storage of unreconstituted lyophilized material).

Principal research-supply applications of HMG and gonadotropin preparations:

Reproductive-endocrinology rodent models. Mouse and rat models of controlled ovarian stimulation use HMG (often paired with subsequent hCG for the ovulation trigger) to study follicular development, oocyte maturation, and superovulation for embryological and developmental-biology research. Mouse superovulation for embryo collection in transgenic-mouse production is a foundational research application of exogenous gonadotropins.

Granulosa-cell and theca-cell culture research. Primary granulosa cells from rodent and human follicles and cultured granulosa-cell lines (e.g., KGN) are studied with FSH (and the combined HMG) to characterize signaling, gene-expression responses, and steroidogenic activity. Theca-cell research analogously uses LH (or HMG for combined activity) to characterize androgen biosynthesis.

Sertoli-cell and Leydig-cell research. Cultured Sertoli cells (rodent primary cells and immortalized lines) are studied with FSH to characterize Sertoli-cell function. Cultured Leydig cells (rodent primary cells and lines such as MA-10) are studied with LH to characterize Leydig-cell steroidogenic responses.

Steroidogenesis pathway research. The detailed enzymatic steroidogenesis pathway (cholesterol → pregnenolone → progesterone / androgens / estrogens via the various CYP450 and HSD enzymes) is studied in gonadal cell models with gonadotropin stimulation as the upstream signal.

HPG-axis perturbation and reconstitution research. Rodent models of GnRH-receptor knockout, pituitary ablation, or pharmacological HPG-axis suppression are reconstituted with exogenous gonadotropins (HMG, recombinant FSH, recombinant LH) to characterize the contribution of gonadotropin signaling to phenotypes of interest.

Polycystic ovarian syndrome (PCOS) research. Rodent PCOS models use gonadotropin manipulation as part of the experimental induction or characterization. Follicular-fluid and serum gonadotropin measurement in PCOS research provides functional readouts of HPG-axis activity.

Comparative bioactivity research. Studies comparing urinary HMG, recombinant FSH, recombinant LH, and recombinant hCG in matched experimental conditions provide research-context information on the contribution of glycoform composition and source preparation to biological activity.

All applications are research-supply context. The preparation is not for human consumption. Nothing on this page describes a clinical protocol or therapeutic use.

HMG sits within the family of clinical and research-supply gonadotropin preparations. The key distinctions are FSH-versus-LH composition, source (urinary versus recombinant), and the standard activity-unit labeling.

Human Menopausal Gonadotropin (HMG) is a combined gonadotropin preparation containing approximately equal biological activity of FSH and LH, historically purified from the urine of postmenopausal women. The original clinical product, Pergonal, was developed in the early 1960s by Bruno Lunenfeld and Piero Donini at Serono and represents one of the foundational preparations in modern reproductive endocrinology, enabling the development of controlled ovarian stimulation and modern assisted reproductive technology.

In research-supply context, HMG serves as a combined-activity gonadotropin tool for studies requiring both FSH and LH activity: controlled ovarian stimulation in rodent models, granulosa-cell and theca-cell research, Sertoli-cell and Leydig-cell research, steroidogenesis-pathway research, HPG-axis perturbation studies, and PCOS research. Recombinant single-component preparations (rFSH, rLH) are alternatives when isolated single-gonadotropin activity is required.

This research-supply preparation is supplied as a lyophilized powder reconstituted with bacteriostatic water and provided for laboratory and research-supply use. It is not a substitute for clinical HMG products dispensed by pharmacies for human use, and is not intended for human consumption. The educational content on this page provides scientific and historical context for the research-supply application only.