Reference

A plain-language glossary for the terms that keep appearing

The learn pages, approaches, and Start Here all lean on a shared vocabulary — perimenopause, HRT, peptide therapy, bioidentical, compounding. This page defines each term plainly, without the clinical hedge or the marketing gloss, so the rest of the site makes more sense the first time you read it.

Bioidentical
Hormones structurally identical to those produced by the body, as opposed to synthetic analogues; commonly used to describe estrogen and progesterone formulations in HRT that mirror endogenous hormone chemistry. The term describes molecular structure, not sourcing or regulatory status.
BPC-157
Body Protection Compound 157 — a peptide studied for tissue repair, gut-lining integrity, and anti-inflammatory signalling. It is the primary peptide in Eterna Femme's Recovery & Vitality approaches.
CJC-1295
A growth hormone-releasing hormone analogue that extends the natural GH pulse window during deep sleep without blunting the body's pulsatile secretion rhythm. It anchors the Sleep & Restoration approaches.
Compounding pharmacy
A licensed pharmacy that prepares custom medications to a patient's specific prescription rather than dispensing a mass-manufactured product; the regulatory model under which clinical-curator-prescribed peptides are prepared to pharmaceutical identity, purity, and potency standards.
Epitalon
A tetrapeptide studied for its role in telomere elongation and pineal gland regulation; part of the Longevity & Cellular Health approaches alongside MOTS-c.
GLP-1 agonist
A class of metabolic peptides and drugs — including semaglutide, tirzepatide, and retatrutide — that mimic the gut hormone GLP-1 to regulate insulin secretion and appetite. Retatrutide also agonises GIP and glucagon receptors, making it a triple agonist.
Growth hormone (GH)
A pituitary hormone governing tissue repair, lean-mass maintenance, and metabolic signalling; secreted in discrete overnight pulses whose amplitude and frequency decline with age and are disrupted by the hormonal shifts of perimenopause.
HPA axis
The hypothalamic-pituitary-adrenal axis — the body's central stress-response circuit; elevated cortisol from HPA over-activation suppresses GH pulsatility, impairs deep sleep, and accelerates muscle breakdown, making it a core concern in midlife women managing sleep and recovery.
HRT / Hormone Replacement Therapy
The clinical use of exogenous estrogen and/or progesterone to restore hormonal levels during perimenopause and postmenopause; it works on different biological pathways than peptide therapy and is often used alongside rather than instead of a peptide approach. Read more at Peptides & HRT.
Mitochondrial efficiency
The capacity of cells' energy-producing organelles to generate ATP without excess oxidative by-product; mitochondrial efficiency declines with age and hormonal shift, contributing to fatigue and metabolic slowdown that many women first notice in their late 40s.
MOTS-c
A mitochondria-derived peptide that regulates cellular energy metabolism and has been studied for insulin-sensitising effects; part of the Longevity & Cellular Health approaches alongside Epitalon.
Peptide therapy
The therapeutic use of short amino-acid chains (peptides) to signal specific biological pathways — tissue repair, GH release, cellular longevity, or metabolic function — as a targeted research-backed intervention distinct from hormone replacement or general supplementation.
Perimenopause
The hormonal transition that precedes the final menstrual period, typically beginning in the mid-to-late 40s; characterised by fluctuating estrogen and progesterone, cycle irregularity, and symptom patterns — sleep changes, mood shifts, body-composition change — that may span four to ten years before menopause is reached. See the perimenopause staging guide.
Postmenopause
The phase beginning 12 months after a woman's final menstrual period, defined by a sustained low-estrogen baseline; bone-density loss accelerates, metabolic risk shifts, and the cellular-longevity and bone approaches become the primary areas of focus. Read the menopause guide.
Telomere
The protective cap at the end of each chromosome that shortens with every cell division; telomere length is used as a marker of biological aging, and Epitalon has been studied for its ability to activate telomerase, the enzyme that rebuilds this cap.
Vasomotor symptoms
The cluster of temperature-dysregulation symptoms — hot flashes, night sweats, sudden chills — driven by hypothalamic thermoregulatory dysfunction as estrogen levels fluctuate or fall; one of the most common and disruptive symptom groups in perimenopause.