Health & treatment glossary — drugs, mechanisms, metrics & trials

Drugs

Finasteride: A 5-alpha-reductase inhibitor that lowers scalp DHT to slow hair loss; FDA-approved for male pattern loss.
Liraglutide: First-generation GLP-1 receptor agonist; active ingredient in Saxenda and Victoza.
Melatonin: Hormone the brain releases at night to signal sleep; also a supplement used to shift sleep timing.
Minoxidil: A topical (or off-label oral) treatment that prolongs the hair growth phase; OTC for pattern hair loss.
Semaglutide: GLP-1 receptor agonist; active ingredient in Wegovy, Ozempic, and Rybelsus.
Tirzepatide: Dual GIP/GLP-1 receptor agonist; active ingredient in Mounjaro and Zepbound.
TRT: Prescription testosterone (gel, injection, or pellet) for men with clinically low, symptomatic levels.

Mechanism

Circadian rhythm: The ~24-hour internal clock that governs sleep, alertness, and hormone release, set mainly by light.
DHT: A potent androgen made from testosterone that miniaturizes scalp follicles in pattern hair loss.
GIP: Second gut hormone targeted by tirzepatide (Zepbound, Mounjaro). Dual GIP/GLP-1 action drives stronger weight loss than single-agonist drugs.
GLP-1: Glucagon-like peptide-1 receptor agonist — class of drugs that mimic a gut hormone to reduce appetite and slow stomach emptying.
Incretin: Gut hormone (GLP-1 or GIP) that stimulates insulin secretion in response to oral glucose.
NAD+: A coenzyme central to energy metabolism and DNA repair that declines with age.
SHBG: A blood protein that binds sex hormones; high SHBG lowers usable (free) testosterone.

Metrics

A1C: Average blood sugar over the past 2-3 months. Healthy: <5.7%. Pre-diabetes: 5.7-6.4%. Diabetes: ≥6.5%.
BMI: Body mass index = weight (kg) / height (m)². Overweight: 25-29.9. Obese: ≥30. FDA threshold for Wegovy/Zepbound: BMI ≥30, or ≥27 with weight-related condition.
Free testosterone: The fraction of testosterone not bound to proteins and available to tissues — often more telling than total.
Sleep latency: How long it takes to fall asleep after lights out — typically 10–20 minutes in healthy sleepers.

Conditions

Androgenetic alopecia: The most common cause of hair thinning, driven by genetics and DHT sensitivity.
Hypogonadism: Clinically low testosterone plus symptoms — diagnosed by blood tests, not symptoms alone.
Type 2 diabetes: Chronic insulin resistance with relative insulin deficiency. Diagnosis: A1C ≥6.5%.

Clinical trials

SCALE: Pivotal trial of Saxenda (liraglutide 3.0 mg) for chronic weight management.
SELECT trial: Landmark 2023 cardiovascular outcomes study showing semaglutide (Wegovy) cut major cardiovascular events by 20% in adults with prior heart disease.
STEP 1: Pivotal 68-week trial that earned Wegovy its FDA weight-loss approval. Average 14.9% body weight loss vs 2.4% placebo.
SURMOUNT-1: Pivotal 72-week trial behind Zepbound's FDA approval. Average 20.9% body weight loss at the 15 mg dose.
SURPASS-2: Head-to-head trial of Mounjaro (tirzepatide) vs Ozempic (semaglutide) in T2D.
SUSTAIN 6: CV outcomes trial of Ozempic (semaglutide) in T2D. 26% MACE reduction.

Regulatory

Compounded: Non-FDA-approved version mixed by a licensed pharmacy. Cheaper than brand-name but quality varies. Only legal when the FDA declares a drug in shortage.
MTC: Rare thyroid cancer; GLP-1s carry an FDA black-box warning for personal or family history of MTC or MEN 2.
NPI: 10-digit identifier for US healthcare providers, publicly searchable via NPPES Registry.
Prior authorization: Insurance step that requires your doctor to document medical necessity before the plan will cover the drug. Adds 3-14 days but is often required for GLP-1s.

Other terms

Bioavailability: The share of a dose that actually reaches the bloodstream in active form.
Third-party tested: Independent lab verification that a supplement matches its label and is free of meaningful contaminants.
Titration: Gradual dose increase over weeks to build tolerance and minimize GI side effects. Typical GLP-1 schedule: 4-week steps up to the maintenance dose.

Drugs

Finasteride

A 5-alpha-reductase inhibitor that lowers scalp DHT to slow hair loss; FDA-approved for male pattern loss.

Liraglutide

First-generation GLP-1 receptor agonist; active ingredient in Saxenda and Victoza.

Melatonin

Hormone the brain releases at night to signal sleep; also a supplement used to shift sleep timing.

Minoxidil

A topical (or off-label oral) treatment that prolongs the hair growth phase; OTC for pattern hair loss.

Semaglutide

GLP-1 receptor agonist; active ingredient in Wegovy, Ozempic, and Rybelsus.

Tirzepatide

Dual GIP/GLP-1 receptor agonist; active ingredient in Mounjaro and Zepbound.

TRT

Prescription testosterone (gel, injection, or pellet) for men with clinically low, symptomatic levels.

Also known as: testosterone replacement therapy.

Mechanism

Circadian rhythm

The ~24-hour internal clock that governs sleep, alertness, and hormone release, set mainly by light.

DHT

A potent androgen made from testosterone that miniaturizes scalp follicles in pattern hair loss.

Also known as: dihydrotestosterone.

GIP

Second gut hormone targeted by tirzepatide (Zepbound, Mounjaro). Dual GIP/GLP-1 action drives stronger weight loss than single-agonist drugs.

Also known as: glucose-dependent insulinotropic polypeptide.

GLP-1

Glucagon-like peptide-1 receptor agonist — class of drugs that mimic a gut hormone to reduce appetite and slow stomach emptying.

Also known as: GLP-1 agonist, GLP-1 receptor agonist, GLP-1 RA.

Incretin

Gut hormone (GLP-1 or GIP) that stimulates insulin secretion in response to oral glucose.

NAD+

A coenzyme central to energy metabolism and DNA repair that declines with age.

Also known as: nicotinamide adenine dinucleotide.

SHBG

A blood protein that binds sex hormones; high SHBG lowers usable (free) testosterone.

Also known as: sex hormone-binding globulin.

Metrics

A1C

Average blood sugar over the past 2-3 months. Healthy: <5.7%. Pre-diabetes: 5.7-6.4%. Diabetes: ≥6.5%.

Also known as: HbA1c, hemoglobin A1C.

BMI

Body mass index = weight (kg) / height (m)². Overweight: 25-29.9. Obese: ≥30. FDA threshold for Wegovy/Zepbound: BMI ≥30, or ≥27 with weight-related condition.

Also known as: body mass index.

Free testosterone

The fraction of testosterone not bound to proteins and available to tissues — often more telling than total.

Sleep latency

How long it takes to fall asleep after lights out — typically 10–20 minutes in healthy sleepers.

Also known as: sleep onset latency.

Conditions

Androgenetic alopecia

The most common cause of hair thinning, driven by genetics and DHT sensitivity.

Also known as: pattern hair loss, male pattern baldness, female pattern hair loss.

Hypogonadism

Clinically low testosterone plus symptoms — diagnosed by blood tests, not symptoms alone.

Also known as: low testosterone, low T.

Type 2 diabetes

Chronic insulin resistance with relative insulin deficiency. Diagnosis: A1C ≥6.5%.

Also known as: T2D, type 2 diabetes mellitus.

Clinical trials

SCALE

Pivotal trial of Saxenda (liraglutide 3.0 mg) for chronic weight management.

SELECT trial

Landmark 2023 cardiovascular outcomes study showing semaglutide (Wegovy) cut major cardiovascular events by 20% in adults with prior heart disease.

STEP 1

Pivotal 68-week trial that earned Wegovy its FDA weight-loss approval. Average 14.9% body weight loss vs 2.4% placebo.

Also known as: STEP 1 trial.

SURMOUNT-1

Pivotal 72-week trial behind Zepbound's FDA approval. Average 20.9% body weight loss at the 15 mg dose.

Also known as: SURMOUNT trial.

SURPASS-2

Head-to-head trial of Mounjaro (tirzepatide) vs Ozempic (semaglutide) in T2D.

SUSTAIN 6

CV outcomes trial of Ozempic (semaglutide) in T2D. 26% MACE reduction.

Regulatory

Compounded

Non-FDA-approved version mixed by a licensed pharmacy. Cheaper than brand-name but quality varies. Only legal when the FDA declares a drug in shortage.

Also known as: compounded semaglutide, compounded tirzepatide.

MTC

Rare thyroid cancer; GLP-1s carry an FDA black-box warning for personal or family history of MTC or MEN 2.

Also known as: medullary thyroid carcinoma.

NPI

10-digit identifier for US healthcare providers, publicly searchable via NPPES Registry.

Also known as: National Provider Identifier.

Prior authorization

Insurance step that requires your doctor to document medical necessity before the plan will cover the drug. Adds 3-14 days but is often required for GLP-1s.

Also known as: PA, prior auth.

Other terms

Bioavailability

The share of a dose that actually reaches the bloodstream in active form.

Third-party tested

Independent lab verification that a supplement matches its label and is free of meaningful contaminants.

Also known as: third-party testing, NSF Certified, USP Verified.

Titration

Gradual dose increase over weeks to build tolerance and minimize GI side effects. Typical GLP-1 schedule: 4-week steps up to the maintenance dose.

Health & treatment terms, explained

Drugs

Mechanism

Metrics

Conditions

Clinical trials

Regulatory

Other terms

Health & treatment terms, explained

Drugs

Mechanism

Metrics

Conditions

Clinical trials

Regulatory

Other terms