Medical Glossary

5-Amino-1MQ is a small-molecule inhibitor of the enzyme nicotinamide N-methyltransferase (NNMT), not a peptide, sold online as a research chemical for weight loss.

503A compounding pharmacy is a state-licensed pharmacy where a pharmacist or physician prepares a drug for a specific, identified patient based on a valid prescription.

503B outsourcing facility is a drug compounder registered with FDA that operates under manufacturing-quality rules, without needing a prescription for each named patient before compounding.

AHK-Cu is a copper-binding tripeptide, L-alanyl-L-histidyl-L-lysine-Cu2+, studied for stimulating hair follicle growth in laboratory experiments.

Appeal refers to a request to your health insurer or the Health Insurance Marketplace to review a decision that denied a benefit or payment.

Bacteriostatic water is sterile water containing 0.9% or 1.1% benzyl alcohol as a preservative, used only as a diluent for other injectable drugs.

Best GLP-1 for weight loss is a question the trial data can only partly answer.

BPC-157 (Body Protection Compound-157) is a synthetic peptide of 15 amino acids derived from a fragment of a gastric protein.

Brand-name vs generic refers to two ways the same active ingredient can reach the market: under a manufacturer's trademarked name, or, once patents and exclusivity expire, as an FDA-approved generic.

CagriSema is an investigational once-weekly combination of the amylin analog cagrilintide and the GLP-1 medicine semaglutide, dosed together at 2.4 mg each.

Cash pay is paying the full price of a medication yourself, without using insurance to cover any part of the cost.

Cash price of GLP-1s refers to what Zepbound and Wegovy cost when paid out of pocket through the manufacturer's own self-pay channel, rather than through insurance.

Category 1 vs Category 2 peptides refers to FDA's interim sorting of substances nominated for the 503A bulks list.

Certificate of analysis is a supplier's test report stating a batch's identity, purity and other quality measures.

CJC-1295 is a long-acting analog of growth hormone-releasing hormone (GHRH) studied in two 2006 randomized trials for its ability to raise growth hormone and IGF-1 levels.

Coinsurance is the percentage of a covered service's cost you pay, such as 20%, after you've met your deductible.

compounded peptide is a peptide medication custom-mixed by a compounding pharmacy for an individual patient rather than manufactured by an FDA-approved drug maker.

Compounded semaglutide is a custom-mixed version of the GLP-1 drug semaglutide made by a licensed pharmacy rather than a drug manufacturer.

Compounded tirzepatide is a custom-mixed version of the GLP-1/GIP drug tirzepatide made by a compounding pharmacy rather than a drug manufacturer.

Compounding pharmacy is an umbrella term for a pharmacy or facility that combines, mixes, or alters ingredients into a drug tailored to a patient's needs.

Copay is a fixed dollar amount, such as $20, that you pay for a covered service or prescription after you've met your deductible.

Coverage exclusion is a service or drug your health plan's terms say it will not pay for or cover.

Deductible is the amount you pay for covered health care services before your insurance plan starts to pay.

Dihexa is a synthetic angiotensin IV-based compound studied in animals for memory and synaptic effects, developed as a blood-brain-barrier-permeable analog by a Washington State research group.

DSIP is a nonapeptide first isolated from rabbit cerebral venous blood in 1977 and studied for insomnia, with the sequence Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu.

Dual agonist refers to a medicine engineered to activate two separate hormone receptors, usually GIP and GLP-1, at once in a single molecule.

Dulaglutide is the active ingredient in Trulicity, a once-weekly GLP-1 receptor agonist injection.

Epitalon is a synthetic tetrapeptide (Ala-Glu-Asp-Gly) developed from epithalamin, a pineal extract studied by Russian researcher Vladimir Khavinson.

FDA bulk drug substances list refers to FDA's lists of active ingredients nominated for use in compounding, sorted into review categories that determine eligibility.

FDA drug shortage list is a public database of drugs FDA has determined are in shortage in the United States, updated daily with new and resolved shortages.

Formulary is the list of prescription drugs a health plan covers, also called a drug list.

Foundayo is the FDA-approved brand name for orforglipron, an oral GLP-1 receptor agonist tablet, approved April 1, 2026 to reduce excess body weight and keep it off.

FSA is an arrangement through your employer that lets you pay for many out-of-pocket medical expenses with tax-free dollars.

GHK-Cu is a copper-bound tripeptide, glycyl-L-histidyl-L-lysine, found naturally in the body.

GIP is a 42-amino-acid hormone released from intestinal K cells that stimulates insulin release after eating.

GLP-1 (glucagon-like peptide-1) is a hormone your gut releases after you eat.

GLP-1 alternatives are FDA-approved weight-management medications that do not act on the GLP-1 receptor, plus non-drug approaches.

GLP-1 cost refers to what a patient or payer spends on drugs like Ozempic, Wegovy, Mounjaro, and Zepbound, which varies by list price, Medicare-negotiated price, self-pay offer, and insurance coverage.

GLP-1 injections are once-weekly subcutaneous shots, such as Zepbound and Mounjaro, that deliver a GLP-1 or dual GIP/GLP-1 medication under the skin.

GLP-1 medications list refers to the FDA-approved GLP-1 and dual GIP/GLP-1 brands covered here: Wegovy, Ozempic, Rybelsus, Zepbound, Mounjaro and Foundayo.

GLP-1 receptor agonist is a medication that activates the GLP-1 receptor.

GLP-2 is a gut hormone released from intestinal L cells that promotes intestinal growth, absorption and blood flow, distinct from GLP-1, the hormone targeted by weight-loss drugs.

Glutathione is a tripeptide of glutamate, cysteine and glycine made in the body.

Glutathione injection is a compounded IV or IM product containing the antioxidant tripeptide glutathione, prepared by a 503A pharmacy from bulk glutathione powder.

Growth hormone peptides is an umbrella term for GHRH analogs and GH-releasing peptides marketed to raise the body's own growth-hormone output, including tesamorelin, sermorelin, CJC-1295, ipamorelin and GHRP compounds.

Growth hormone secretagogue refers to any compound that prompts the pituitary gland to release growth hormone, grouped under an umbrella that includes GHRH analogs and GH-releasing peptides.

HSA is a savings account that lets you set aside money on a pre-tax basis to pay for qualified medical expenses.

IGF-1 LR3 is a modified, longer-acting analog of insulin-like growth factor 1 sold online as a research peptide.

Incretin refers to a class of gut hormones, GIP and GLP-1, that boost insulin release after eating more than glucose alone would trigger.

Injectable peptides are peptide drugs delivered by subcutaneous or intramuscular injection, the route used by many approved peptide medications.

Kisspeptin is a naturally occurring hormone that triggers GnRH release through the GPR54 receptor and drives puberty and reproductive hormone signaling.

KPV is a tripeptide of lysine, proline and valine derived from alpha-MSH(11-13) and studied for wound healing and inflammation in mice.

Letter of medical necessity is a statement from your prescriber explaining why a specific drug is medically necessary for you.

LillyDirect is Eli Lilly's direct-to-consumer healthcare platform, offering home delivery and telehealth options for Lilly medications.

Liraglutide is a glucagon-like peptide-1 (GLP-1) receptor agonist sold as two FDA-approved brand-name injections: Victoza, for type 2 diabetes, and Saxenda, for chronic weight management.

LL-37 is a 37-residue antimicrobial peptide made only by humans, released from the precursor protein hCAP-18 by neutrophils.

Lyophilized peptide refers to a peptide that has been freeze-dried into a stable powder by removing water under vacuum after freezing.

Manufacturer savings card is a discount offered directly by a drug maker to lower the out-of-pocket cost for patients with commercial insurance or who pay without insurance.

Medicaid coverage is the extent to which a state Medicaid program pays for GLP-1 medications, which varies because weight-loss drugs are optional while diabetes drugs are mandatory.

Medicare Part D is the Medicare prescription drug benefit that has historically excluded GLP-1 medications used only for weight loss.

Melanotan II is a synthetic peptide analog of melanocyte-stimulating hormone marketed online as an injectable or nasal-spray tanning product.

Membership fee is the recurring charge a telehealth program bills for provider consultations, messaging, and platform access, separate from any medication cost.

Most-favored-nation pricing refers to a policy aiming to bring American drug prices in line with those paid by similar nations.

MOTS-c is a 16-amino-acid peptide encoded by a short open reading frame within mitochondrial DNA.

Mounjaro is a brand-name tirzepatide injection FDA-approved to improve blood sugar control in adults and children 10 and older with type 2 diabetes.

NAD+ is a coenzyme found in every cell that helps transfer energy from food into a usable form, and is chemically a dinucleotide rather than a peptide.

NAD+ injection is a compounded product delivering the coenzyme nicotinamide adenine dinucleotide by IV or subcutaneous injection, marketed for anti-aging and wellness uses.

Natural GLP-1 boosters are foods and supplements marketed to raise your own GLP-1 hormone.

Newest GLP-1 medications refers to the most recently approved and the still-pending drugs in the GLP-1 class.

NovoCare Pharmacy is the pharmacy service Novo Nordisk operates to deliver GLP-1 medications directly to patients, with self-pay pricing that does not require insurance.

Oral GLP-1 medications are pill or tablet forms of GLP-1 receptor agonist drugs, taken by mouth instead of injected.

Orforglipron is a GLP-1 receptor agonist taken as a once-daily oral tablet, rather than an injection, that binds to and activates the human GLP-1 receptor.

Out-of-pocket maximum is the most you have to pay for covered services in a plan year before your health plan starts covering 100% of the costs of covered benefits.

Ozempic is an FDA-approved weekly semaglutide injection indicated for adults with type 2 diabetes, used alongside diet and exercise to improve blood sugar control.

Patient assistance program is a program, usually run by a drug's manufacturer, that provides medicine at no cost to patients who meet its eligibility rules, typically insurance status and income.

Pen injector is a prefilled device used to inject GLP-1 medications subcutaneously, either as a single-dose pen used once and discarded or a multi-dose pen reused for several doses.

Peptide is a short chain of amino acids, which FDA defines as 40 or fewer.

Peptide side effects are the adverse reactions reported for both FDA-approved peptide drugs and unapproved compounded peptides.

Peptides for muscle growth refers to growth-hormone secretagogues, IGF-1 LR3, follistatin and MGF, marketed online to increase lean mass.

Peptides for sleep refers to a small group of peptides marketed for insomnia, chiefly DSIP and epitalon, neither backed by strong human evidence.

Peptides for testosterone refers to peptide hormones and peptide-based medicines that can influence testosterone production through the hypothalamic-pituitary-gonadal (HPG) axis.

Peptides for weight loss refers to a mix of two FDA-approved peptide drugs and several unapproved peptides marketed online for fat loss.

Pharmacy benefit manager is a company that negotiates drug rebates with manufacturers, builds the formulary and its rules, and reimburses pharmacies for a health plan's prescription claims.

Pinealon is a synthetic tripeptide, Glu-Asp-Arg, developed by Russian peptide researchers and studied mainly in rats.

Polypeptide is the general chemistry term for a chain of amino acids joined by peptide bonds, with no fixed length limit.

Prior authorization is approval your health plan requires before it will cover a specific service or prescription, such as a GLP-1 medication.

PT-141 is the development code for bremelanotide, a melanocortin receptor agonist sold as the FDA-approved drug Vyleesi.

Rapamycin is the generic name for sirolimus, an mTOR-inhibitor drug FDA-approved in 1999 as Rapamune, for organ-rejection prevention after kidney transplant and for lymphangioleiomyomatosis.

Research use only is a label vendors put on peptides to claim they are not drugs for human use.

Retatrutide is an investigational triple hormone receptor agonist that activates the GIP, GLP-1 and glucagon receptors at once, tested for obesity and type 2 diabetes.

Rybelsus is an FDA-approved oral semaglutide tablet indicated for adults with type 2 diabetes, taken once daily on an empty stomach.

Saxenda is the brand name for liraglutide 3 mg, a once-daily GLP-1 injection approved for chronic weight management.

Selank is a synthetic peptide analog of tuftsin, studied in rats and in small Russian studies of anxiety patients, and sold online for anxiety.

Semaglutide is a GLP-1 receptor agonist sold under three FDA-approved brand names, each with its own indication: Wegovy, Ozempic, and Rybelsus.

Semaglutide vs tirzepatide is a comparison between semaglutide, a GLP-1 receptor agonist, and tirzepatide, a dual GIP and GLP-1 receptor agonist.

Sermorelin is a 29-amino-acid analog of growth hormone-releasing hormone (GHRH) that stimulates the pituitary to release growth hormone.

SS-31 is the development code for elamipretide, an FDA-approved mitochondria-targeted peptide drug sold under the brand Forzinity.

Step therapy is a type of prior authorization that requires trying a lower-cost drug proven effective for most people with your condition before the plan covers a costlier one.

TB-500 is a synthetic seven-amino-acid fragment of the natural protein thymosin beta-4, covering amino acids 17 to 23 with an acetyl group at one end.

Testosterone replacement therapy is prescription testosterone, a steroid hormone rather than a peptide, given to men whose bodies produce too little of it.

Thymosin alpha-1 is a 28-amino-acid peptide naturally occurring in the thymus that supports T-cell maturation.

Tirzepatide is a dual GIP and GLP-1 receptor agonist medication sold under two FDA-approved brand names, Zepbound and Mounjaro.

TrumpRx is a federal website listing self-pay prices for certain brand-name medications, including Wegovy, Ozempic, and Zepbound, under agreements the White House announced with drugmakers.

Vial and syringe refers to a GLP-1 dosage form supplied as a glass vial rather than a prefilled pen, drawn up and injected with a separate syringe.

VIP peptide refers to vasoactive intestinal peptide (VIP), a 28-amino-acid neuropeptide that acts as a neurotransmitter and helps regulate blood vessels, immune responses, and secretion of certain substances.

Wegovy is an FDA-approved semaglutide brand sold as both a weekly injection and a daily tablet under one label.

Wegovy at Costco / CVS refers to the retail pharmacy channels Novo Nordisk names as partners for its Wegovy self-pay pricing, not a separate discounted price at those stores.

Wegovy cost is the price a patient pays for Wegovy, which depends on insurance coverage and dosage form.

Wegovy coupon is Novo Nordisk's manufacturer savings offer that lowers the monthly cost of Wegovy for patients with commercial insurance or who pay without insurance.

Wegovy generic name is semaglutide, the nonproprietary name of the active ingredient in Wegovy, which is sold as an injection and as a tablet under one FDA label.

Wegovy pill is the oral tablet form of Wegovy, taken once daily and sharing one FDA label with the Wegovy injection.

Wolverine stack is an informal, online-only name for combining the peptides BPC-157 and TB-500, sold for injury recovery.

Zepbound is a brand-name tirzepatide injection FDA-approved for chronic weight management and moderate to severe obstructive sleep apnea in adults with obesity.