Glossary
Plain-English definitions of the terms we use.
Concierge telehealth lives at the intersection of clinical medicine, pharmacy regulation, and state law. Patients shouldn't need a medical license to make sense of it. These are the 39 terms that show up across the Vektor site, explained the way we'd explain them to a friend.
Peptides
- BPC-157(Body Protective Compound 157)
- A 15-amino-acid peptide derived from a protein found in human gastric juice. Most-searched peptide of the last five years. Used in cycles for soft-tissue injury recovery, gut barrier integrity, and post-surgical healing. Working theory: BPC-157 extends the body's natural tissue-repair signals through VEGF and nitric-oxide pathways. Under FDA category review; compounded availability depends on current 503A posture.
- TB-500(Thymosin Beta-4)
- A synthetic version of Thymosin Beta-4, a naturally-occurring protein. Paired with BPC-157 for systemic tissue repair — particularly post-injury or after intensive training blocks. Under FDA category review; compounded availability is protocol-by-protocol and depends on indication.
- Sermorelin
- A 29-amino-acid fragment of growth-hormone-releasing hormone (GHRH). Stimulates the pituitary to release the body's own GH in a natural pulsatile pattern — unlike exogenous HGH which suppresses endogenous production. The gentle entry peptide; modest response curve, well-tolerated.
- CJC-1295
- A modified GHRH analog with a longer half-life than Sermorelin — extending GHRH signaling through the night. Usually prescribed paired with Ipamorelin for dual-pathway GH release. Workhorse of peptide therapy: deep sleep, lean body composition, recovery from training.
- Ipamorelin
- A selective ghrelin receptor agonist that triggers growth- hormone release through the secretagogue pathway — without the cortisol or prolactin spike that older GHRPs (GHRP-2, GHRP-6) cause. Pairs with CJC-1295 for the cleanest dual- mechanism GH protocol available.
- Tesamorelin(Egrifta)
- Stronger GHRH analog. FDA-approved (as Egrifta) for visceral adipose tissue reduction in HIV-associated lipodystrophy and increasingly used off-label by metabolic clinicians for visceral fat, body recomposition, and glycemic control. Compounded forms also available.
- GHK-Cu(Copper peptide)
- A copper-binding tripeptide with research support for skin remodeling, collagen synthesis, hair restoration adjunct, and wound healing. Available injectable or topical. Long history of use in dermatology and cosmetics.
- Thymosin Alpha-1
- Immune-modulating peptide with a long clinical history outside the U.S. Used to support immune resilience in patients dealing with chronic stress, frequent illness, or post-viral recovery. Available through 503A compounding under current FDA posture.
- NAD+(Nicotinamide adenine dinucleotide)
- A cellular cofactor central to mitochondrial energy production and DNA repair. Levels decline with age. Supplemented via injection (loading phase + maintenance) or nasal spray (lower intensity, daily use). Common in longevity protocols.
- Glutathione
- The body's master antioxidant — a tripeptide of cysteine, glycine, and glutamate. Supports detoxification, oxidative stress management, and recovery. Available as injectable, oral capsule, or nasal spray; format choice depends on bioavailability priorities.
- DSIP(Delta sleep-inducing peptide)
- A peptide studied for slow-wave sleep promotion and cortisol regulation. Prescribed in cycles for patients dealing with disrupted sleep architecture, shift-work patterns, or stress-driven cortisol issues. Not for daily-forever use.
- Epitalon
- A pineal-gland-derived tetrapeptide studied for telomerase activation and circadian regulation. Most patients use it in 10–20 day cycles, repeated quarterly. Common in longevity protocol stacks.
- MOTS-c
- A mitochondrial-derived peptide with research support for metabolic regulation, exercise capacity, and insulin sensitivity. Used by patients with metabolic resistance who have already optimized the foundational levers (sleep, training, nutrition).
- PT-141(Bremelanotide)
- On-demand injectable for sexual desire — acts on melanocortin receptors in the central nervous system rather than peripherally. Different mechanism from PDE5 inhibitors. FDA-approved for women with hypoactive sexual desire disorder and used off-label for men.
Hormones
- TRT(Testosterone replacement therapy)
- Replacement of endogenous testosterone with exogenous testosterone — typically injectable cypionate or transdermal cream. Standard of care for confirmed primary hypogonadism. Suppresses natural production while on therapy, which is why many men start with enclomiphene first.
- Enclomiphene(Enclomiphene citrate)
- A selective estrogen receptor modulator (SERM). Blocks estrogen receptors at the hypothalamus, which the body interprets as low estrogen and responds by producing more LH and FSH — and more endogenous testosterone. Preserves fertility, unlike traditional TRT.
- Testosterone cypionate
- Injectable form of testosterone, the most common TRT format. Typically dosed once or twice weekly. Compounded through 503A pharmacies or available as commercial (FDA-approved) products. Schedule III controlled substance — requires Ryan Haight Act compliance when prescribed via telehealth.
- Anastrozole(Arimidex)
- Aromatase inhibitor — blocks the conversion of testosterone into estradiol. Used selectively during TRT when estradiol rises out of the optimal range. Dosed conservatively and only when labs justify it; not a default add-on.
- Gonadorelin
- A GnRH analog used during TRT to preserve testicular function and fertility. Easier-to-access alternative to HCG. Often added to injectable testosterone protocols for men who want to maintain natural production while on therapy.
- Estradiol(E2)
- The primary form of estrogen produced by the ovaries. Bioidentical estradiol (transdermal gel, patch, oral, or compounded cream) is first-line hormone therapy for perimenopausal and menopausal symptoms — vasomotor symptoms, sleep disruption, mood, and bone health support.
- Progesterone
- Bioidentical hormone used in cycled or continuous regimens for endometrial protection in women with a uterus, and sometimes for sleep and mood support on its own. Oral micronized progesterone is the standard format.
- Biest cream
- Compounded combination estrogen cream — typically estradiol + estriol (50/50 or 20/80 ratios), sometimes with estrone. Used for vaginal and systemic symptoms. Preferred when fine dose adjustment matters.
- HPG axis(Hypothalamic-pituitary-gonadal axis)
- The feedback loop that regulates sex-hormone production: hypothalamus → pituitary (LH/FSH) → testes/ovaries → testosterone/estradiol. Negative feedback means high circulating hormone suppresses the upstream signal. Enclomiphene and TRT intervene at different points in this loop.
GLP-1 / Metabolic
- GLP-1(Glucagon-like peptide-1)
- A gut hormone that slows gastric emptying, increases satiety, and improves insulin sensitivity. Semaglutide and tirzepatide mimic GLP-1 (and in tirzepatide's case, GIP as well) at much higher doses than the body produces naturally.
- Semaglutide(Wegovy · Ozempic)
- A weekly GLP-1 receptor agonist for weight management and type-2 diabetes. Trial data shows ~15% body-weight reduction at therapeutic doses. Compounded and FDA-approved branded forms are both available; access depends on current 503A regulatory posture.
- Tirzepatide(Zepbound · Mounjaro)
- A dual GLP-1 + GIP receptor agonist with stronger weight- reduction data than semaglutide (~20% body-weight reduction at therapeutic doses). FDA-approved as Zepbound (weight) and Mounjaro (diabetes). Compounded availability is more constrained than semaglutide.
- A1C(Hemoglobin A1C · HbA1c)
- A blood test that reflects average blood-glucose levels over the past 2–3 months. Standard marker for prediabetes (5.7– 6.4%) and diabetes (≥6.5%). Tracked at baseline and at regular intervals during GLP-1 therapy.
Regulatory
- Ryan Haight Act(Ryan Haight Online Pharmacy Consumer Protection Act)
- Federal law requiring a live, real-time audio-video evaluation with a licensed physician before any controlled substance can be prescribed via telehealth. Testosterone (Schedule III) is the most-affected medication for hormone telehealth. A 5- minute web quiz does NOT satisfy this requirement.
- CPOM(Corporate Practice of Medicine doctrine)
- State-level doctrine restricting non-physician entities from practicing medicine. Strongest in New York (which is why many telehealth clinics opt out of NY). Compliance requires a physician-owned Professional Corporation (PC) delivering care, with management services structured carefully to avoid fee- splitting issues.
- FDA shortage list
- FDA-maintained list of medications experiencing supply shortages. When a brand-name drug is on the list, 503A pharmacies may legally compound a similar version under defined criteria. Semaglutide and tirzepatide spent time on and off this list, which is why compounded availability has shifted year-over-year.
Pharmacy
- 503A pharmacy(FDA 503A compounding pharmacy)
- State-licensed compounding pharmacies that prepare medications for individual patients based on a prescription. Different from 503B outsourcing facilities (which produce in larger batches under FDA oversight). Most peptide and TRT compounds come from 503A pharmacies.
- 503B outsourcing facility
- FDA-registered outsourcing facilities that compound medications in larger batches under stricter FDA oversight than 503A. Some compounded GLP-1 medications come from 503B facilities. Higher regulatory bar; typically larger operations.
- LegitScript-certified
- Certification required by Google and Meta to advertise prescription medications. Signals that a pharmacy operates legitimately within U.S. regulatory frameworks — not gray- market or overseas. The floor for any reputable telehealth + pharmacy partnership.
- Compounded medication
- A medication prepared specifically for an individual patient by a licensed pharmacist, based on a prescription. Different from manufactured FDA-approved drugs (which are mass-produced in a single standardized form). Allows custom dosing, formulations, and ingredient combinations not commercially available.
Care model
- Concierge medicine
- A care model where patients pay a monthly retainer for direct physician access — fewer patients per clinician, longer visits, direct messaging. Inverse of the quiz-funnel / prescriber-of-the-day model. Healthcare-equivalent of a boutique professional service.
- Quiz-funnel telehealth
- A scale-first care model: 5–10 minute web questionnaire → prescriber-of-the-day signs the prescription → medication ships → support queue answers questions. Optimized for per-patient unit economics, not clinical relationship. Hims, Ro, Henry Meds, Mochi all operate this model.
- MSO + PC structure(Management Services Organization + Professional Corporation)
- A two-entity legal structure required for CPOM-strict states (especially NY). The MSO handles business operations (platform, marketing, billing); the PC — owned by licensed physicians — actually delivers clinical care. They operate under a Management Services Agreement with a fixed fee structure (not revenue-share, to avoid fee-splitting).
- PHI(Protected Health Information)
- Any information that can identify a patient AND relates to their health, healthcare provision, or healthcare payment. HIPAA-regulated. Vektor's marketing site (vektor.health) does NOT collect PHI; clinical platforms (Bask, Ola) do, under signed Business Associate Agreements.
- BAA(Business Associate Agreement)
- Legal contract required under HIPAA between a covered entity (healthcare practice) and any business associate (vendor) that handles PHI. Vektor maintains signed BAAs with every vendor that touches PHI — clinical platform, pharmacy partner, lab network.
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