Best Peptides for Ultramarathon & Backyard Ultras: What the Community Uses (2026)

The compounds most used by ultrarunners in our community are the gut-and-tendon peptide BPC-157 and the mitochondrial peptide MOTS-c — tied at the top — followed by the non-peptide PPARδ agonist Cardarine, because the ultra problem is not speed but survival: keeping a wrecked gut working, burning fat when glycogen is gone, and recovering from volumes that would injure a normal runner. This is the extreme-end spoke of our endurance cluster: it answers what people actually reach for when the distance stretches past 100 miles, explains the ultra-specific science honestly, and tells you the doping status of every option before you read another word.

Most "peptides for ultrarunning" content is just a recovery listicle with the word "ultra" pasted on top. We do it differently. The headline ranking below comes from first-party usage data — what ~2,400 ProtocolPlus users training for ultras actually track — and the science is built around the three things that actually break an ultrarunner: Runner's Gut over 12 to 48 hours, fuel that runs out, and cumulative tissue load. For the science on any single molecule we link up to its dedicated guide, and for everyday road and trail running we point you to the hobby-runner spoke, so this page stays the clean decision hub for the extreme end.

TL;DR. The ProtocolPlus ultra community's most-used compounds are BPC-157 and MOTS-c (tied at 22% each), then Cardarine (18%) and NAD+ (12%) — a usage signal, not proof of what works or is safe. None has a human ultra trial; Cardarine is a non-peptide research chemical halted for causing cancer in animals; and for a drug-tested ultra (UTMB, championship 100-milers) only NAD+ survives the WADA filter.

Key Takeaways

• What the ultra community uses (not an efficacy ranking): across ~2,400 ProtocolPlus ultrarunners, BPC-157 and MOTS-c tie for #1 at 22% each (528 users each), followed by Cardarine (18%, 432) and NAD+ (12%, 288) (ProtocolPlus app data).
• The frame is different from road running. Ultras break people through the gut, through fuel depletion, and through sheer cumulative load — so the top picks are a gut-and-tendon peptide (BPC-157) and a mitochondrial-efficiency peptide (MOTS-c), not a speed aid.
• Usage is not proof. No compound on this list has a human ultra-endurance trial behind it. BPC-157's gut data is from animals, MOTS-c's performance data is from mice, and the recovery peptides are mostly animal-evidenced.
• Cardarine is not a peptide and is dangerous. GW-501516 is a research chemical whose development was halted after it caused dose-dependent cancers in rats across multiple organs. It is on this list because people use it, not because it is safe.
• Tested ultras are a near-total wipeout. UTMB and championship 100-milers are WADA-tested. Filter the selector to "tested" and only NAD+ survives — and NAD+ is no proven ultra aid.
• The boring levers still win. Gut training, fat-adaptation built over months, and a tendon base that survives the volume do more for a 100-miler than anything in a vial.

What peptides do ultrarunners actually use?

Across ~2,400 ProtocolPlus users training for ultras, BPC-157 and MOTS-c are tied as the most-tracked compounds at 22% each, followed by the non-peptide PPARδ agonist Cardarine (18%) and the cofactor NAD+ (12%). This is a usage ranking from our own app data, not a clinical verdict on what works best for ultra-distances — and several of these carry real risk.

The split tells the ultra story directly. Unlike the road-running crowd, who lean recovery-first, the ultra cohort splits its top spot between two very different bets: BPC-157 for the gut and connective tissue that take the worst beating over 12-to-48-hour efforts, and MOTS-c for the mitochondrial efficiency that matters most once glycogen is gone and you are running on fat. Cardarine sits third as the most-whispered-about "fuel-economy" compound, and NAD+ rises higher here than almost anywhere else (12% versus single digits on the hub) because multi-day formats make between-effort cellular recovery the obsession. The tail runs through TB-500 (10%) for systemic tissue resilience, then the oral exercise-mimetics SLU-PP-332 (9%) and Stenabolic (7%).

These shares come only from our community-usage dataset and describe behavior, not efficacy. A compound can be widely used and barely evidenced at the same time, that describes this entire list. Read the chart below as "what ultrarunners reach for," then cross-check it against the ultra-specific science and the doping read further down, where the picture changes hard.

Citation capsule. Among ~2,400 ProtocolPlus users who logged ultramarathon as a goal, the most-tracked compounds were BPC-157 (22%, 528 users) and MOTS-c (22%, 528), tied for first, followed by Cardarine/GW-501516 (18%, 432) and NAD+ (12%, 288). This is first-party usage data reflecting what the community uses, not a clinical efficacy ranking and not a safety ranking. Source: ProtocolPlus app data (goals/ultramarathon.json), 2026.

ProtocolPlus app data, n ≈ 2,400 users training for ultras (goals/ultramarathon.json, 2026). A usage signal, not a clinical efficacy or safety ranking.

The ultra community's top picks (by usage)

The four most-used ultra compounds are BPC-157, MOTS-c, Cardarine, and NAD+ — a gut-and-tendon peptide, a mitochondrial-efficiency peptide, a carcinogenic research chemical, and a recovery cofactor. Each card pairs the usage share with the honest reason ultrarunners pick it and the caveat that comes with it.

These four account for roughly three-quarters of ultra usage in our cohort. Notice how different this is from a road-running ranking: the gut peptide is tied for first, because over 100-plus miles the limiter is rarely your legs and very often your stomach. Popularity here tracks "solves an ultra-specific failure point" far more than "proven in people."

The long tail (ranks 5–7): the remaining ~26% of usage spreads across TB-500 (10%) for systemic soft-tissue resilience under huge cumulative load, and the oral exercise-mimetics SLU-PP-332 (9%) and Stenabolic (7%), both non-peptide research chemicals with mouse-only data. Each gets a mini-section below, linking up to its compound hub.

Why ultras are a different problem entirely

An ultramarathon does not break you the way a marathon does — it breaks you through your gut, through fuel that runs out, and through cumulative tissue damage and sleep loss that compound over hours or days — and that is exactly why the ultra community's picks look nothing like a road-runner's. Understanding these four failure points is what separates a real ultra rationale from a recycled recovery listicle, so this is where the spoke goes deep.

To put the scale in view: the backyard-ultra ("last runner standing") world record now stands at 119 consecutive hourly loops — 798 km over five days — set by Phil Gore at Dead Cow Gully in 2024, while the women's individual record reached 95 loops, roughly 637 km, at Big's Backyard Ultra in October 2025 (The Running Channel, "Backyard Ultra World Record," 2025, retrieved 2026-06-17). At those volumes, the question is no longer "how fast" but "what fails first," and the honest answer is almost never the cardiovascular system people try to drug.

Failure point 1 — Runner's Gut (the signature ultra problem)

The first thing to fail in a long ultra is usually the stomach, and the numbers are stark. In a study of a 161-km (100-mile) ultramarathon, 96% of finishers reported gastrointestinal symptoms, nausea was the single most common complaint, and among runners who dropped out, nausea was cited as a reason by 90.5% of them (Stuempfle & Hoffman, "Gastrointestinal distress is common during a 161-km ultramarathon," Journal of Sports Sciences, 2015, retrieved 2026-06-17). For ultrarunners, "Runner's Gut" is not a nuisance; it is the leading reason people fail to finish.

The mechanism is gut ischemia. During prolonged, hard, or hot running, blood is shunted away from the splanchnic (gut) circulation toward working muscles and skin; that drop in gut blood flow slows gastric emptying, impairs absorption, and damages the intestinal lining, which sets up the cramping, nausea, and the endotoxin leak that makes you feel systemically awful. This is the exact biology behind the community's #1 pick: BPC-157 is a pentadecapeptide isolated from gastric juice, stable in the gut, and studied in animals for protecting and healing the intestinal lining through angiogenesis and tight-junction repair (Sikiric et al., reviewed in PMC, "BPC-157 as a cytoprotectant of the gastrointestinal tract," 2024, retrieved 2026-06-17). That mechanistic fit — a gut-protective peptide for a gut-limited sport — is why BPC-157 ties for first here when it sits mid-pack on the general endurance hub. The crucial caveat, stated plainly: that protection has been shown in rodents with chemically induced gut injury, never in a human running an ultra.

Failure point 2 — fuel runs out (the fat-adaptation bet)

The second failure point is energy. You store only enough carbohydrate for roughly a couple of hours of hard running, so any effort past that depends on burning fat — and the body's ability to oxidize fat at race pace becomes the limiter. This is "fat-adaptation," and it is built primarily by months of aerobic training that raise mitochondrial density and fat-oxidation enzymes, not by a vial. The metabolism genuinely shifts under ultra-load: after 24 hours of continuous ultra-endurance exercise, human muscle mitochondria became less efficient (a 6–9% drop in the P/O ratio) but raised their fat-oxidation capacity by 39–41% (Fernström et al., "Reduced efficiency, but increased fat oxidation, in mitochondria after 24-h ultraendurance exercise," Journal of Applied Physiology, 2007, retrieved 2026-06-17).

This is the link the mitochondrial compounds target. MOTS-c, the co-#1, is a mitochondrial-derived peptide that activates AMPK — the same nutrient-sensing pathway exercise activates — and is itself exercise-induced; in mice it improved running performance across age groups (Reynolds et al., "MOTS-c is an exercise-induced mitochondrial-encoded regulator," Nature Communications, 2021, retrieved 2026-06-17). Cardarine (PPARδ) and Stenabolic (REV-ERB) come from the "exercise in a pill" line of work, where in mice a PPARδ agonist plus training raised running endurance (Narkar et al., "AMPK and PPARδ Agonists Are Exercise Mimetics," Cell, 2008, retrieved 2026-06-17). The catch no ultra listicle states: every one of those numbers is from rodents, and the human relevance for a 100-miler is unproven.

Failure point 3 — connective tissue under huge mileage

The third failure point is structural. Ultra training means cumulative mileage that lives close to the edge of overuse injury — tendons, ligaments, and fascia absorb load for hours with no recovery window mid-race. The recovery-and-tissue peptides bet on this link: BPC-157 (again) and TB-500 are used for tendon and soft-tissue resilience under load, the logic being that the runner who holds a 16-week build without breaking down beats the one who builds for six and then breaks for three. It is a real lever, because in ultra training availability is everything — but whether these peptides deliver it in humans is unproven, and both are mostly animal-evidenced.

Failure point 4 — sleep deprivation and the backyard format

The last failure point is unique to the longest formats. In a backyard ultra or a multi-day, you are not just fatigued, you are sleep-deprived for 24, 48, or 100-plus hours, and recovery between hourly loops or daily stages becomes the entire contest. This is why NAD+ ranks notably higher in the ultra cohort (12%) than on the broader endurance hub: the bet is on a cellular-energy cofactor to support the relentless between-effort turnaround. The honest read is the same as everywhere else here — the rationale is biological, the human ultra evidence is absent, and even the delivery question (whether injected NAD+ raises intracellular levels) is debated.

Citation capsule. Ultra-endurance has four signature limiters: Runner's Gut from exercise-induced gut ischemia (GI symptoms in 96% of finishers at 161 km; nausea the top reason for DNFs, 90.5%; Stuempfle & Hoffman, J Sports Sci 2015); fuel depletion driving reliance on fat oxidation (which rose 39–41% as mitochondrial efficiency fell 6–9% after 24 h of ultra-exercise; Fernström et al., J Appl Physiol 2007); cumulative connective-tissue load; and sleep deprivation in multi-day/backyard formats. The community's picks map onto these limiters — BPC-157 (gut/tissue), MOTS-c/Cardarine (fat-oxidation), NAD+ (between-effort recovery) — but the supporting data is animal or mechanistic, never a human ultra trial.

Mechanism families: how the ultra picks group

Sorted by what they actually do, the seven candidates fall into three families — gut-and-tissue recovery peptides, mitochondrial exercise-mimetics, and a metabolic cofactor. Grouping them this way shows why the ultra ranking looks the way it does and keeps each molecule's deep science on its own hub.

Gut & tissue recovery — BPC-157, TB-500

This family targets the gut and the connective tissue that ultras destroy. BPC-157 is the standout because it is the only compound here with a gut-specific mechanism, which is exactly why it ties for #1 in a sport where the stomach is the leading DNF cause; it is also used for tendon resilience. TB-500 (a thymosin β-4 fragment) is the systemic-tissue companion, used for soft-tissue durability under huge cumulative load. Neither has a human ultra trial, and both are mostly animal-evidenced. We keep them shallow here on purpose — the deep tendon, gut, and injury-healing science is its own intent. Full science: the BPC-157 complete guide and the TB-500 complete guide.

Mitochondrial exercise-mimetics — MOTS-c, Cardarine, SLU-PP-332, Stenabolic

This family chases fuel economy: oxidize more fat, mimic the exercise signal, run longer before the tank empties. MOTS-c is the peptide of the group and the co-#1; the other three are small molecules, not peptides — a distinction every competitor blurs. Cardarine (PPARδ) and Stenabolic (REV-ERB) have the loudest animal endurance stories and the worst safety records; SLU-PP-332 (ERR) is the newest and most preclinical, increasing running capacity in mice but with no human data at all. For the lead compound, see the MOTS-c complete guide; for the research-chemical trio, the Cardarine (GW-501516) guide, the SLU-PP-332 guide, and the Stenabolic (SR9009) guide.

Metabolic cofactor — NAD+

The cofactor family is the upstream-support idea: keep the cellular energy machinery topped up between efforts. NAD+ is central to mitochondrial energy metabolism and declines with age, which is the rationale — but the ultra benefit is indirect and unproven, and IV-to-intracellular delivery is debated. Its one practical virtue is regulatory: it is the only top pick not currently WADA-prohibited. More: the NAD+ guide.

Which ultra compound fits your situation?

The decision turns on three questions the selector asks — injectable or oral, drug-tested or not, and how experienced you are — and for ultras the drug-tested question is brutal: tested ultras like UTMB wipe out almost the entire list. The matrix below sets all seven candidates against the dimensions that actually decide it, including route and WADA status.

This table is the "why" behind the usage ranking — editorial context, not the headline. The selector quiz at the top runs the same logic interactively. The single most important filter is drug-tested: choose it and the list collapses to one option, because almost every compound ultrarunners use is prohibited in sport.

The ultra demands, scored by what each compound targets

Map the three things that actually break ultrarunners — gut tolerance, the fat-oxidation engine, and recovery from massive volume — against what each compound is reaching for, and the picture explains the whole ranking: no single compound covers all three, and the safest options cover the least. This view is the differentiator no ultra listicle shows.

The grouped bars below score each leading compound (editorially, 0–5) on how directly it targets each ultra-specific demand, with its WADA status flagged. BPC-157 owns the gut column outright. MOTS-c and Cardarine own the fat-oxidation column, but Cardarine carries the carcinogenicity flag. NAD+ leans recovery and is the only bar that is not banned. Read it as a coverage map, not an efficacy claim — every score is "what it aims at," not "what it proves."

Discussed in the ultra scene but not in our cohort

A few things get talked about constantly in ultra circles but barely register in our usage data — and one of them, the most-hyped of all, is the one with the worst record. Covering these honestly is part of being a complete spoke; we keep each brief because none is a community pick.

AICAR is the original AMPK-activating "exercise mimetic" that raised endurance in sedentary mice; it gets named whenever fat-adaptation pharmacology comes up, but it is not something our cohort tracks, it has no human ultra data, and it is a WADA-prohibited metabolic modulator. SS-31 / Elamipretide, a mitochondria-targeting peptide that stabilises the inner-membrane lipid cardiolipin, is the most mechanistically interesting "efficiency" peptide ultrarunners ignore; it is in human trials for mitochondrial disease, not for athletic endurance. And the honest punchline belongs to carbohydrate and gut training — not a peptide at all. The single most effective intervention for Runner's Gut is repeatedly practising high-carbohydrate intake in training to expand intestinal absorption, which is legal, free, and the actual standard of care for the sport's leading failure point. If you want the highest-yield "ultra gut" upgrade, it is a training protocol, not a vial.

The doping reality: tested ultras leave almost nothing

For a drug-tested ultrarunner the ranking above is mostly a list of ways to fail a test — six of the seven candidates are on the WADA Prohibited List, and the major championship events are tested. This is the section that matters most if you race UTMB, a 100-mile national championship, or any IAU/World Athletics-sanctioned ultra, and it is where community usage and competition reality diverge hardest.

The split is simple. The metabolic modulators (class S4.4) — Cardarine, Stenabolic, SLU-PP-332, AICAR, and MOTS-c, which is explicitly named on the list as a prohibited AMPK activator — are banned at all times. The non-approved substances (class S0) — BPC-157 (on the list since January 2022) and TB-500, neither approved for human use by any regulator — are banned at all times as well. Only NAD+ is not currently prohibited, which is the entire reason it is the sole survivor of the selector's drug-tested filter. The "but it's just recovery" defence does not exist: a BPC-157 violation carries the same four-year default ban that excludes an athlete from Boston, the World Marathon Majors, and most ultras worth running (Marathon Handbook, "What Are Peptides, And Why Is Every Middle-Aged Runner Talking About BPC-157?," 2026, retrieved 2026-06-17).

Citation capsule. Under the WADA Prohibited List, the ultra candidates split across two classes plus one allowed compound: S4.4 metabolic modulators (Cardarine/GW-501516, Stenabolic/SR9009, SLU-PP-332, AICAR, and MOTS-c, named as a prohibited AMPK activator) and S0 non-approved substances (BPC-157, on the list since January 2022, and TB-500). Only NAD+ is not currently prohibited. Drug-tested ultrarunners (UTMB, championship 100-milers) should assume a substance is prohibited unless verified. Sources: WADA Prohibited List S4.4/S0; USADA advisories (GW1516, BPC-157); Marathon Handbook (BPC-157 ban context).

Why Cardarine does not belong in any ultra plan

The ultra community's #3 pick is the one we flag hardest: Cardarine is not a peptide, it has no human safety data, and its development was abandoned because it caused cancer in animals. No fat-oxidation upside justifies that, and the doping sanction makes the math worse.

Cardarine (GW-501516) is a PPARδ agonist that produced strong fat-oxidation and endurance effects in mice — which is exactly why it circulates in ultra forums as a "fuel-economy" compound. But its drug development was halted after long-term rodent studies showed dose-dependent cancers across multiple organs, a finding reported in the developer's preclinical toxicology data and treated as established by anti-doping authorities, who have issued explicit health warnings (USADA, "What athletes should know about GW1516", retrieved 2026-06-17; Sport Integrity Australia, "GW1516 — popular but deadly," 2018, retrieved 2026-06-17). For an unproven endurance benefit, an animal carcinogenicity signal plus an unknown human safety profile is not a trade any rational ultrarunner should make, and for a tested athlete it is a near-certain four-year ban on top. We rank it because people use it; we are telling you not to.

What's realistic to expect — and how to read the claims

If you are weighing one of these for your next 100-miler, the realistic expectation is "no measurable, proven benefit in a human ultra" — and the testimonials you will find on forums are exactly the kind of evidence that misleads. Setting that expectation honestly is more useful than any ranking.

Three habits keep you grounded. First, separate animal numbers from human promises: "improved running in mice" and "39–41% more fat oxidation after 24 hours of exercise" are real findings, but the first is in rodents and the second is a description of normal ultra physiology, not a drug effect — neither predicts what a vial does for your race. Second, distrust the finish-line story: anyone using these compounds is also training huge volume, dialing in gut tolerance, and sleeping and eating with intent, so a good race gets credited to the peptide when the preparation did the work. Third, weight the downside correctly: for an unproven upside you are accepting an unknown long-term safety profile (and, for Cardarine, a known carcinogenicity signal), research-grade vials of uncertain potency and purity, and — if you race anything tested — a near-certain sanction. The interventions that reliably move an ultra are the unglamorous ones: months of aerobic base for fat-adaptation, deliberate gut training, a tendon base that survives the mileage, and a fueling and sleep plan for the back half. Nothing on this community ranking belongs in that category yet.

Go deeper: the hub and your sibling sports

This is the extreme-end spoke of our endurance cluster — if your running is everyday road or trail rather than 100-mile-plus, or you want the full aerobic-performance overview, start with the hub or the hobby-runner guide instead. Each inherits this page's honest framing and goes deep on its own context.

For the molecule-level science behind the co-leaders, see the BPC-157 guide and the MOTS-c guide; and before sourcing anything, how to vet peptide quality and are peptides legal.

What the community does is not what is proven, or safe

Treat the ultra usage ranking as a popularity signal shaped by mechanism appeal, forum hype, and availability — not as evidence of what works or what is safe over 100-plus miles. The clearest proof is that the community's #3 compound, Cardarine, is a research chemical whose own development was abandoned because it caused cancer in animals.

Three honest framings sit on top of every number here. First, no compound on this page has a positive human ultra trial — BPC-157's gut data is animal, MOTS-c's performance data is mouse, the recovery peptides are mostly animal-evidenced, and Cardarine's endurance signal is rodent-only. Second, the gut and fat-oxidation findings are real biology, not drug proof: the 96% GI-symptom rate and the 39–41% fat-oxidation rise describe what ultrarunning does to a body, and they explain why people reach for these compounds — but they are not evidence that a vial changes the outcome. Third, research-grade vials carry quality risk — unknown potency, purity, and sterility — on top of compounds that are themselves unproven, a hazard no usage statistic captures.

Our take: Read this page as two layers that disagree. The usage chart tells you what real ultrarunners reach for; the science and safety read tell you how little supports it. The most defensible ultra decision for almost everyone is the unglamorous one: train the gut, build the fat-adaptation and tendon base over months, and treat everything on this list as experimental at best and, in Cardarine's case, dangerous.

Who should not go near these

These compounds are not for anyone racing tested ultras, not for anyone outside research or clinical oversight, and Cardarine and Stenabolic are not for anyone, full stop. The honest contraindication list here is short and firm.

A few hard lines. Tested ultrarunners (UTMB, championship and national 100-milers, any World Athletics/IAU-sanctioned event) should treat the entire top of this list as a failed test waiting to happen — six of seven candidates are WADA-prohibited, and "it was just for my gut" is not a defence. Anyone considering Cardarine or Stenabolic should weigh that these are non-peptide research chemicals with a carcinogenicity signal (Cardarine) and near-zero oral bioavailability plus off-target effects (Stenabolic) — there is no version of the risk-reward that favours them. And for every research peptide here, the responsible answer is the same: there is no validated safe-use protocol for ultra-endurance, so they belong in a trial or under a clinician, not in a self-directed cycle the week before a race. None of this page is a substitute for that conversation.

Frequently Asked Questions

The bottom line

If you came here for a single "best peptide for ultramarathon," the honest answer is uncomfortable: there isn't one with human evidence behind it. The ultra community's co-leaders make mechanistic sense — BPC-157 for the gut that ends more ultras than tired legs, MOTS-c for the fat-burning efficiency you live on once glycogen is gone — but both rest on animal and mouse data, not a single human ultra trial. Cardarine, the #3 pick, carries a disqualifying carcinogenicity record on top of being a non-peptide research chemical. And the interventions that actually move a 100-miler are the ones no vial can sell you: months of fat-adaptation, deliberate gut training, and a tendon base that survives the volume.

For a drug-tested ultrarunner the practical answer is shorter still: almost everything here is prohibited, and the one compound that is not (NAD+) is not proven to work. The selector at the top narrows the field to your constraints — injectable or oral, tested or not — but the most defensible ultra decision is the one this whole page keeps circling back to: train the gut and the engine that actually respond, and treat these compounds as experimental at best and dangerous at worst. From here, the natural next reads are the endurance hub for the full aerobic-performance picture, the hobby-runner guide if your miles are everyday rather than extreme, and the BPC-157 guide for the science on the gut peptide at the top of this list.

Sources

• Stuempfle KJ, Hoffman MD. "Gastrointestinal distress is common during a 161-km ultramarathon." Journal of Sports Sciences, 2015, 33(17):1814–21. Retrieved 2026-06-17. https://pubmed.ncbi.nlm.nih.gov/25716739/
• Fernström M, Bakkman L, Tonkonogi M, et al. "Reduced efficiency, but increased fat oxidation, in mitochondria from human skeletal muscle after 24-h ultraendurance exercise." Journal of Applied Physiology, 2007, 102(5):1844–9. Retrieved 2026-06-17. https://pubmed.ncbi.nlm.nih.gov/17234801/
• Sikiric P, et al. "BPC-157, a pentadecapeptide cytoprotectant of the gastrointestinal tract" (review). PMC, 2024. Retrieved 2026-06-17. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12396989/
• Reynolds JC, Lai RW, Woodhead JST, et al. "MOTS-c is an exercise-induced mitochondrial-encoded regulator of age-dependent physical decline and muscle homeostasis." Nature Communications, 2021, 12:470. Retrieved 2026-06-17. https://www.nature.com/articles/s41467-020-20790-0
• Narkar VA, Downes M, Yu RT, et al. "AMPK and PPARδ Agonists Are Exercise Mimetics." Cell, 2008, 134(3):405–415. Retrieved 2026-06-17. https://www.sciencedirect.com/science/article/pii/S0092867408008386
• The Running Channel. "What Is The Backyard Ultra World Record?" 2025. Retrieved 2026-06-17. https://therunningchannel.com/backyard-ultra-record/
• Marathon Handbook. "What Are Peptides, And Why Is Every Middle-Aged Runner Suddenly Talking About BPC-157?" 2026. Retrieved 2026-06-17. https://marathonhandbook.com/what-are-peptides-and-why-is-every-middle-aged-runner-suddenly-talking-about-bpc-157/
• U.S. Anti-Doping Agency (USADA). "What Should Athletes Know About GW1516?" and "BPC-157: Experimental Peptide Creates Risk for Athletes." Retrieved 2026-06-17. https://www.usada.org/spirit-of-sport/what-should-athletes-know-gw1516/
• Sport Integrity Australia. "GW1516 — Popular but Deadly." 2018. Retrieved 2026-06-17. https://www.sportintegrity.gov.au/news/integrity-blog/2018-10/gw1516-popular-deadly
• World Anti-Doping Agency. "The Prohibited List" — S4.4 Metabolic Modulators (GW1516, SR9009, AICAR, MOTS-c, SLU-PP-332 class), S0 Non-Approved Substances (BPC-157, TB-500). Retrieved 2026-06-17. https://www.wada-ama.org/en/prohibited-list
• ProtocolPlus. "Community goal-usage data: ultramarathon" (goals/ultramarathon.json). First-party app data, 2026. n ≈ 2,400 users training for ultras. Usage signal, not a clinical efficacy or safety ranking.