A physician-curated resource on the molecules, mechanisms, and clinical evidence behind performance medicine. Written by Anup Pradhan, MD and Sonya Jagwani, MD.
Most longevity brands sell protocols. We explain them. This page is our commitment to transparency — every molecule we use, the mechanism behind it, and the clinical evidence as it stands today. No hype. No black-box formulas.
How NAD+ depletion drives aging and why precursor supplementation is the metabolic foundation of longevity medicine.
Read more ↓Why GHRH analogues preserve pulsatile GH release without the risks of exogenous HGH.
Read more ↓The Wolverine Protocol — how two peptides cover all three phases of tissue repair.
Read more ↓Beyond weight loss — the pleiotropic effects on heart, brain, and metabolic health.
Read more ↓How platelet-derived extracellular vesicles signal collagen and elastin repair at the cellular level.
Read more ↓19 peptides moving from Category 2 to Category 1 — what it means for patients and providers.
Read more ↓PRP, BMAC, A2M, and micro-fragmented adipose tissue — how the body's own biology repairs joints.
Read more ↓The nutrient-sensing pathways that govern aging — and the compounds that modulate them.
Read more ↓The cascading biology of hormonal decline — and why 75% of women seeking care receive none.
Read more ↓Nicotinamide adenine dinucleotide (NAD+) participates in over 400 enzymatic reactions throughout the body. It is indispensable for mitochondrial ATP generation, sirtuins-mediated gene regulation, and the PARP family of enzymes responsible for DNA damage repair. Without sufficient NAD+, cells lose their capacity to produce energy efficiently, repair genomic damage, and regulate inflammatory signaling.
NAD+ levels decline measurably with age through two primary mechanisms. First, PARP-1 consumes large quantities of NAD+ as it repairs accumulated DNA damage. Second, CD38 — an enzyme upregulated during chronic low-grade inflammation — degrades NAD+ at an accelerating rate. The result is a progressive bioenergetic deficit that compromises mitochondrial function and cellular resilience.
Precursor molecules nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN) have shown consistent ability to raise circulating NAD+ levels in controlled human studies. This biochemical target engagement is well-established across multiple trial designs. We think of NAD+ replenishment as establishing a metabolic floor — a baseline of cellular energy that allows other therapeutic interventions (peptides, hormones, tissue repair agents) to function as intended.
It is worth noting that while the biochemistry is robust, functional outcome data in large human cohorts remains heterogeneous. Some trials show improvements in markers of vascular health and exercise tolerance; others show less clear-cut clinical benefit. This is why we position NAD+ as a foundational layer of the protocol stack rather than a standalone intervention.
| Mechanism | Role of NAD+ |
|---|---|
| Mitochondrial respiration | Electron carrier in oxidative phosphorylation (ATP synthesis) |
| DNA repair | Substrate for PARP-1 and PARP-2 enzymes |
| Gene regulation | Required cofactor for sirtuin deacetylases (SIRT1-7) |
| Immune signaling | Modulates CD38-dependent calcium signaling in immune cells |
After age 30, the pituitary gland's secretion of growth hormone (GH) declines at roughly 14% per decade — a process known as somatopause. This decline contributes to progressive sarcopenia (loss of lean muscle mass), increased visceral adiposity, reduced skin thickness and elasticity, diminished bone mineral density, and impaired recovery from injury.
Exogenous GH replacement (synthetic HGH) addresses these deficits but introduces a significant problem: it delivers constant, supraphysiologic GH levels that suppress the hypothalamic-pituitary axis's natural feedback loop. The body stops producing its own GH, creating dependency and elevating risks including insulin resistance, fluid retention, and potential mitogenic effects.
Sermorelin works differently. As a growth hormone-releasing hormone (GHRH) analogue, it stimulates the pituitary to release GH in its natural pulsatile pattern — predominantly during deep sleep cycles. This preserves the negative feedback loop and maintains physiologic GH kinetics. The downstream effects include activation of satellite cells for muscle repair, stimulation of chondrocyte proliferation in cartilage, and enhanced extracellular matrix (ECM) protein synthesis.
In our protocols, sermorelin is often paired with NAD+ supplementation. The rationale: NAD+ ensures the mitochondrial energy supply is adequate, while sermorelin provides the anabolic signaling that directs that energy toward tissue repair and regeneration. One without the other is less effective than the combination.
Tissue healing proceeds through three overlapping phases: inflammation, proliferation, and remodeling. Most single-agent approaches target only one of these phases. The combination of BPC-157 and TB-500 is designed to address all three — which is why it has earned the name "Wolverine Protocol" among patients and practitioners.
BPC-157 is a 15-amino acid peptide originally isolated from gastric juice. Its primary mechanism involves upregulation of vascular endothelial growth factor (VEGF), which drives angiogenesis — the formation of new blood vessels. This is particularly important in hypovascular tissues like tendons, ligaments, and menisci, where poor blood supply is the primary bottleneck to healing. BPC-157 also promotes fibroblast migration and proliferation, accelerating the scaffolding phase of wound repair.
TB-500 is a synthetic fragment of Thymosin Beta-4, a naturally occurring protein involved in actin polymerization — the cytoskeletal remodeling that cells undergo during migration and tissue organization. TB-500 mobilizes progenitor cells to injury sites and modulates pro-inflammatory cytokine expression, dampening excessive inflammation without eliminating the signaling necessary for repair.
Together, they provide complementary coverage. TB-500 manages the inflammatory phase through cytokine modulation while mobilizing stem cells. BPC-157 drives the proliferative phase through VEGF-mediated vascularization and fibroblast activation. Both contribute to the remodeling phase by improving the architectural quality of newly deposited collagen fibers.
| Healing Phase | BPC-157 | TB-500 |
|---|---|---|
| Inflammation | Indirect (vascular support) | Cytokine modulation, stem cell mobilization |
| Proliferation | VEGF upregulation, fibroblast activation | Actin remodeling, progenitor cell recruitment |
| Remodeling | Improved collagen fiber architecture | Enhanced tissue organization |
Typical dosing: BPC-157 at 200–500 mcg daily via subcutaneous injection; TB-500 at 2–5 mg twice weekly during a 4-week loading phase, then reduced to maintenance. All dosing requires physician supervision and individual titration.
GLP-1 receptor agonists are broadly recognized for their weight-loss effects, but the clinical significance of this drug class extends well beyond adipose reduction. GLP-1 receptors are expressed in the heart, brain, kidneys, vasculature, and pancreas, and activating them produces measurable effects across each of these systems.
Cardiovascular effects: GLP-1RAs relax vascular pericytes through potassium-ATP (K-ATP) channel activation, restoring microvascular perfusion in tissues with compromised blood flow. Clinical data shows reduced rates of major adverse cardiovascular events (MACE), and mechanistic studies demonstrate improved microcirculation — a finding relevant to post-MI recovery and chronic heart failure management.
Neurological effects: In the central nervous system, GLP-1 receptor activation has demonstrated the ability to alleviate endoplasmic reticulum (ER) stress, regulate autophagy pathways, suppress neuroinflammatory signaling, and reduce phosphorylation of Tau protein — a hallmark of neurodegenerative pathology. Early-stage clinical research is exploring applications in Alzheimer's disease and Parkinson's disease, with translational evidence that is compelling but not yet definitive.
Metabolic reprogramming: Beyond simple caloric restriction, GLP-1RAs promote the browning of white adipose tissue — converting metabolically inactive fat stores into thermogenically active tissue. They also reduce systemic inflammatory burden by lowering circulating levels of C-reactive protein and pro-inflammatory interleukins. This metabolic recalibration is why patients often report improvements in energy and cognitive clarity that exceed what weight loss alone would predict.
Cutaneous longevity is the maintenance of both the structural integrity and the immune function of the skin barrier over time. Skin is the body's largest organ and one of the first to show measurable signs of biological aging: collagen degradation, elastin fragmentation, impaired wound healing, and dysregulated pigmentation. Our approach treats the skin as a target organ for longevity intervention, not merely a cosmetic surface.
Exosomes are extracellular vesicles ranging from 30 to 200 nanometers in diameter. They function as intercellular communication vehicles, transporting proteins, messenger RNA, and microRNA between cells. Platelet-derived exosomes, in particular, carry growth factors and signaling molecules that instruct fibroblasts and keratinocytes to upregulate collagen synthesis, enhance elastin production, and modulate melanocyte activity. Clinical observations show measurable reductions in wrinkle depth, improved skin hydration, and more uniform pigmentation following exosome-based protocols.
Tretinoin remains the gold standard for cellular-level skin remodeling. By binding to retinoic acid receptor gamma (RAR-gamma), tretinoin directly induces procollagen gene expression while simultaneously blocking matrix metalloproteinases (MMPs) — the enzymes that degrade existing collagen. Decades of clinical use and rigorous trial data make tretinoin one of the most evidence-supported molecules in dermatology.
Phloretin, a polyphenol derived from apple bark, activates the Nrf2 antioxidant pathway, inhibits ferroptosis (iron-dependent cell death), and suppresses UV-induced inflammatory cascades. In our Skin Longevity protocol, phloretin functions as a protective layer that shields the regenerative work being done by exosomes and tretinoin from ongoing environmental damage.
| Agent | Primary Mechanism | Clinical Outcome |
|---|---|---|
| Exosomes (PRP-derived) | Intercellular signaling via growth factors + RNA | Wrinkle reduction, hydration, pigment modulation |
| Tretinoin | RAR-gamma binding; collagen induction + MMP blockade | Increased dermal thickness, reduced photodamage |
| Phloretin | Nrf2 activation; ferroptosis inhibition | UV protection, reduced oxidative damage |
In 2023, the FDA moved 19 peptides from Category 1 to Category 2 on its bulk drug substance list, effectively restricting compounding pharmacies from preparing them. The affected molecules included BPC-157, TB-500 (Thymosin Beta-4 fragment), CJC-1295, Ipamorelin, and several other peptides widely used in regenerative and performance medicine. This regulatory shift removed patient access to compounds that many physicians considered clinically valuable.
In February 2026, HHS announced that 14 of the 19 restricted peptides are expected to return to Category 1 status. Under Category 1 designation, licensed 503A compounding pharmacies can legally prepare these molecules when a physician issues a valid, individualized prescription. This is compounding eligibility — it is not FDA approval. The compounds will not carry FDA-approved labeling, have not completed the traditional new drug application (NDA) process, and are not indicated for specific diseases.
What this means practically: physicians will again be able to prescribe peptides like BPC-157, TB-500, and selected secretagogues through accredited compounding pharmacies. Patient access will be restored for those under appropriate medical supervision. Self-administration without physician oversight remains both legally and medically inappropriate.
Important caveat: As of April 2026, the formal FDA publication confirming the reclassification has not been issued. The HHS announcement establishes intent but is not a final regulatory action. We are monitoring the Federal Register for the official rule and will update this page when it is published.
| Category | Meaning | Status |
|---|---|---|
| Category 1 | Eligible for 503A compounding with valid prescription | Expected for 14 of 19 peptides |
| Category 2 | Restricted from compounding; requires NDA pathway | Current status (pending reclassification) |
| FDA-approved | Full NDA/BLA approval with labeled indications | Not applicable to compounded peptides |
Joint preservation is the clinical anchor of performance longevity. Rather than waiting for degeneration to require surgical replacement, orthobiologics leverage the body's own reparative biology to modulate the intra-articular environment and extend the functional lifespan of joints.
Platelet-Rich Plasma (PRP) concentrates autologous platelets that release a milieu of growth factors — PDGF, TGF-beta, and IGF-1 — which downregulate local inflammation and stimulate connective tissue repair. PRP is most effective in early-stage arthritis and acute tendon or ligament injuries where the biological environment still supports regeneration.
Alpha-2-Macroglobulin (A2M) represents a more targeted approach. A2M is a large plasma protein that functions as a molecular trap for the proteases (matrix metalloproteinases and ADAMTS enzymes) responsible for cartilage degradation in osteoarthritis. By neutralizing these destructive enzymes, A2M can slow or halt the progression of joint degeneration rather than simply managing symptoms.
Bone Marrow Aspirate Concentrate (BMAC) provides a high concentration of mesenchymal stromal cells and interleukin-1 receptor antagonist (IL-1Ra), which counteracts the primary inflammatory driver of joint pain. Harvested from the iliac crest, BMAC is used in advanced joint damage and intra-osseous injections where the biological deficit requires more than growth factor support.
Micro-Fragmented Adipose Tissue (MFAT) offers a structural scaffold alongside a high concentration of perivascular cells. Adipose-derived therapies are particularly effective in cases of moderate to advanced joint wear, providing both cushioning and sustained biological repair signals that persist longer than liquid-phase injectables.
| Orthobiologic | Primary Mechanism | Optimal Application |
|---|---|---|
| PRP | Growth factor delivery; inflammation modulation | Mild arthritis; acute tendon/ligament injuries |
| A2M | Protease inhibition (anti-catabolic) | Moderate arthritis with inflammatory flares |
| BMAC | MSC-rich concentrate; IL-1Ra signaling | Advanced joint damage; intra-osseous injection |
| MFAT | Structural support; adipose-derived repair cells | Joint preservation; cartilage thinning |
The most fundamental layer of longevity medicine involves targeting the nutrient-sensing pathways that govern the rate of aging itself. Two compounds have emerged as the most studied geroprotective agents: rapamycin and metformin.
The mTOR pathway (mechanistic Target of Rapamycin) is a central regulator of cellular growth, proliferation, and autophagy — the process by which cells clear damaged proteins and dysfunctional organelles. When mTOR is chronically activated (as it tends to be in well-fed modern populations), cells prioritize growth over maintenance. The accumulation of cellular debris accelerates aging.
Rapamycin (Sirolimus) inhibits mTOR complex 1, shifting the cellular balance from growth toward repair. In vertebrate models, rapamycin is the most robust lifespan-extending intervention identified to date, showing approximately 24% lifespan extension in a 2025 meta-analysis. In humans, low-dose intermittent protocols (5-10mg weekly) are being explored for their potential to clear senescent cells, enhance immune function, and improve markers of skin aging.
The clinical reality: The 2025 PEARL trial demonstrated that while short-term low-dose rapamycin appears safe, it did not consistently reduce visceral adipose tissue in healthy adults. Long-term effects on muscle mass and immune resilience in primary prevention populations remain unestablished. Rapamycin is a tool with genuine biological rationale and incomplete clinical validation — we present it honestly.
Metformin activates AMPK (AMP-activated protein kinase), the cellular energy sensor that responds to low energy states. While metformin has not demonstrated the same dedicated lifespan extension as rapamycin in non-diabetic animal models, its role in improving insulin sensitivity and reducing metabolic inflammation makes it a valuable adjunct. The hypothesis that metformin and rapamycin may be synergistic — metformin protecting normal cells during periods of mTOR inhibition — is an active area of investigation.
Hormonal decline in women begins earlier and cascades more broadly than most patients are told. Progesterone is typically the first hormone to decline, often starting in the mid-to-late 30s. Estrogen follows in perimenopause (which can begin a full decade before menopause), and testosterone — often overlooked in women's health — declines gradually from the early 30s onward.
The downstream effects are systemic, not isolated. Estrogen receptors exist in virtually every organ system. When estrogen levels drop, the effects cascade across sleep architecture, cognitive function, bone density, cardiovascular protection, body composition, mood regulation, and skin structure. These are not separate conditions requiring separate treatments — they are downstream consequences of the same hormonal mechanism.
The skin connection is where dermatology and hormonal health converge. Estrogen decline triggers up to 30% collagen loss in the first five years of perimenopause. The same hormonal shift driving fatigue and cognitive fog also drives barrier dysfunction, elasticity decline, and accelerated visible aging. This is why Nuviven's approach to skin longevity and hormone optimization are designed as complementary protocols.
The care gap is documented: research consistently shows that approximately 75% of women seeking menopause-related care receive no treatment. This is driven by a combination of provider unfamiliarity with current HRT evidence, lingering fear from the misinterpreted 2002 Women's Health Initiative (WHI) study, and a shortage of trained menopause specialists. The WHI's primary findings — which applied to synthetic conjugated equine estrogens in women over 60 who were 10+ years post-menopause — were broadly misapplied to all forms of HRT across all age groups.
Bioidentical HRT uses hormones that are structurally identical to what the human body produces. Unlike the synthetic conjugated estrogens used in the WHI, bioidentical formulations can be precisely dosed based on individual patient biology and symptoms. The goal is not to override the endocrine system but to restore what has declined to a level that supports normal physiological function.
| Hormone | Decline Onset | Primary Effects of Deficiency |
|---|---|---|
| Progesterone | Mid-to-late 30s | Sleep disruption, anxiety, irregular cycles, PMS intensification |
| Estrogen | Perimenopause (40s) | Hot flashes, cognitive fog, bone loss, collagen decline, cardiovascular risk |
| Testosterone | Early 30s (gradual) | Reduced libido, fatigue, decreased muscle mass, mood changes |
Every week, patients ask me the same question: should I use sermorelin or just go straight to HGH? The answer depends on mechanism.
Read more →RFK Jr. announced 14 previously banned peptides will return to legal compounding status. Here's what actually changed.
Read more →What most women are told vs. what is actually happening biologically. A dermatologist explains the mechanism.
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