Peptides to steer clear of when cancer or tumor growth is a concern

[GrandmaJ]

I came across a peptide avoidance list intended for people with a prior history of tumors or cancer cells, but from what I've seen discussed here, it looks like it's missing pieces. I'd say my intelligence is about average, yet a lot of this science and research material goes right over my head.


https://clinicalpeptidesociety.com/wp-content/uploads/2019/07/PeptidesAvoidCancer.pdf


Is there anyone who maintains a full list of the peps they're staying away from? I'd like to add KPV for hip and knee problems. I just placed an order for P21, hoping to get ahead of memory issues that run in my family. SS31, TA1, and Cartalax are also on my radar, but even after spending weeks digging into the risks, I'm still too scared to commit.

 

[Calm Logic]

While experimenting with AI today, PT-22-28 turned up as an unexpected theoretical cancer concern. That said, PT-22-28 might stop precancerous DNA inflammation, which could mean it is "protective against cancers of the digestive tract (colon/gastric/liver)."

GHK basic (without copper) carried lower risk than GHK-Cu. Even so, both might guard against cancer, colon cancer in particular, through "resetting metastatic gene expression."

Gemini said:


Risk Assessment for Commonly Discussed Peptides & Substances

Peptide / SubstanceCancer/Growth RiskImmunological RiskContraindicationsPrimary MechanismFindings & Related StudiesHGH (Somatropin)HighHighActive malignancy, retinopathy.Full 191-AA Protein.Growth Signaling: Directly promotes systemic proliferation. High ADA risk.Tesamorelin / CJC / SermorelinHighModerate-HighMalignancy history, pregnancy.GHRH / IGF-1 Axis.Growth Signaling: Directly increases IGF-1. PMID: 20472.PT-22-28 (Stable VIP)High (Theoretical)ModerateActive malignancy, hypotension.Potent VPAC Agonist.Survival Signaling: Long-acting VIP; fuels tumor survival via VPAC receptors.TB-4 / TB-500HighModerate-HighSuspected malignancy, sterile abscesses.Angiogenesis / Actin.Tumor Support: Promotes metastasis and blood supply. PMID: 23270513.BPC-157 / DihexaHighLowGI, vascular, or c-Met tumors.VEGF / c-Met Activation.Angiogenic Switch: Potent drivers of oncogenic growth. PMID: 21030672.Melanotan II (MT2)High (Specific)ModerateMelanoma history, atypical nevi.Melanocortin Agonist.Melanocyte Risk: Non-selective; aggressive mole darkening and dysplasia risk.Test-C / hCGModerate-HighModerateProstate/Breast cancer, high RBC.Androgen / LH Mimetic.Hormonal Fuel: High-octane fuel for sensitive tumors. PMID: 37326322.EnclomipheneModerateLowDVT history, visual disturbances.SERM (Pituitary).Feedback Drive: Indirectly raises T/E2; requires prostate monitoring.Ipamorelin / MT1ModerateModerateMalignancy, hypersensitivity.GHS / Selective MC1R.Growth/Tanning: Selective profiles but still stimulate growth pathways.VIP / LL-37 / Kiss-10ModerateModerateNeuroendocrine/Hormone cancers.Receptor Agonists.Mixed Signaling: Pro-survival for tumors in specific environments.CerebrolysinModerateHighPorcine allergy, epilepsy.Porcine Derived.Immunological Risk: Potential for autoimmune reactions to foreign proteins.GHK-CuModerate (Dual)ModerateActive malignancy, copper allergy.Copper / VEGF.Angiogenesis: Copper complex promotes tumor blood supply.AOD-9604 / TesofensineLow-ModerateLowHypertension, cardiovascular disease.hGH Frag / Monoamine.Metabolic Focus: Low proliferative risk; primary concerns are cardiovascular.GHK (Copper-Free)Low-ModerateLowKnown hypersensitivity.Gene Modulation.Oncostatic: Reverses metastatic gene expression (Broad C-Map).PT-141 / Semax / SelankLowLowHypertension, psych crisis.Neuromodulation.Safe Profile: Targeted effects with no known proliferative drive.ARA-290LowLowHypersensitivity.Innate Repair.Non-Proliferative: Anti-inflammatory that avoids EPO-style growth.GLP-1s / CagrilintideLow (Protective)LowMTC history, pancreatitis.Metabolic Incretins.Oncostatic Findings: 36% colorectal cancer risk reduction. PMID: 37952131.TA-1 (Thymosin Alpha-1)Low (Protective)HighOrgan transplant.Immune Modulator.Surveillance: Enhances tumor detection. High anaphylaxis risk.Epithalon / PinealonLow (Protective)LowHypersensitivity.Telomere Stabilization.Oncostatic: Reduces tumor incidence in long-term models.Testagen / ProstamaxLow (Protective)LowHypersensitivity.Reproductive Bioreg.Functional Repair: Normalizes protein synthesis in target glands.Pancreagen / OvagenLow (Protective)LowHypersensitivity.Organ Bioregulators.Normalization: Repairs protein synthesis in pancreas/liver.Bronchogen / CortegenLow (Protective)LowHypersensitivity.Organ Bioregulators.Functional Recovery: Targets lungs and cerebral cortex.Vesugen / CardiogenLow (Protective)LowHypersensitivity.Vascular Bioreg.Endothelial Support: Repairs heart/vessels without driving growth.Cartalax / DSIP / KPVLow (Protective)LowHypersensitivity.Targeted Repair.Safe/Anti-Inflam: Localized repair and NF-κB inhibition.MOTS-c / GlutathioneLowHighSulfur allergy, DAMPs.Metabolic/Antiox.Allergy/Abscess: High risk for anaphylaxis and SubQ/IM sterile abscesses.SS-31 / NAD+LowLowAcute metabolic crisis.Mitochondrial Health.Protective: Supports ATP efficiency; no known growth signaling risk.Carnitine / B12LowModerateCobalt allergy.Nutrient Support.Localized Risk: Abscess risk from high-volume IM injections.

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GLPs show no meaningful cancer risk and are largely protective:

Gemini said:


GLP-1 Cancer Risk: 2026 Consensus

Cancer TypeRisk LevelKey 2026 FindingPrimary MechanismColorectalProtective36% risk reduction (ASCO).Lowers insulin/IGF-1 and GI inflammation.PancreaticNeutralNo causal link in human meta-analysis.Improved glycemic control outweighs early fears.Liver (HCC)ProtectivePrevents NASH/NAFLD progression.Directly reduces hepatic fat and oxidative stress.Breast/OvaryProtectiveReduced hormone-driven tumors.Weight loss lowers peripheral estrogen (aromatase).Kidney/RenalProtectiveReduced oxidative DNA damage.Improves hemodynamics; lowers renal stress.Thyroid (MTC)MonitoringRodent-only; human data remains clear.Warning for MEN2/MTC history only.

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Regarding the peptide LL-37:

Gemini said:


LL-37 acts as a cancer-suppressor in colon, gastric, and blood-based malignancies, but functions as a growth-promoter in lung, breast, and prostate tissues.

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[Calm Logic]

When it comes to GH peptides, and putting dairy in the list as a point of reference:

Gemini said:


SubstanceMechanismOncological Risk ProfileNotable CharacteristicsDairyDietary/Indirect IGF-1Low / BaselineRaises IGF-1 slightly; significant concern mainly for strict oncological diets.SermorelinGHRH AnalogMild RiskShortest half-life; lowest potential for chronic/uncontrolled growth signaling.IpamorelinGHRP (Selective)Mild/Moderate RiskHighly selective for GH; lacks the "hormonal messiness" of older GHRPs.CJC-1295 (No DAC)GHRH AnalogModerate RiskStandard pulse enhancer; more stable than Sermorelin but still pulsatile.TesamorelinGHRH AnalogModerate RiskClinically approved for visceral fat; stronger IGF-1 push than Sermorelin.Tesamorelin + IpamorelinGHRH + GHRP StackElevated RiskSynergistic "turbo" pulse; high peak IGF-1; potent for visceral fat loss.CJC-1295 (No DAC) + IpaGHRH + GHRP StackElevated RiskThe "Classic Stack"; mimics intense natural pulses; overrides natural troughs.GHRP-2 / GHRP-6GHRP (Non-selective)Elevated RiskNon-selective; raises stress hormones (cortisol) and prolactin.HexarelinGHRP (Potent)Elevated RiskStrongest GHRP; highest pulse intensity; potential for rapid desensitization.MK-677 (Ibutamoren)Oral Ghrelin MimeticHigh RiskContinuous GH elevation; potential for 24-hour IGF-1 "over-exposure."CJC-1295 (with DAC)GHRH AnalogHigh RiskCauses "GH bleed"; prevents the body from returning to low-growth baseline.Exogenous HGHDirect HormoneHighest Systemic RiskBypasses feedback loops; direct systemic IGF-1 elevation.IGF-1 LR3Long-Acting IGF-1Extreme / Theoretical DangerPotent inhibitor of apoptosis; persistent signal for cell proliferation.

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[tubby]

Calm Logic said:

When it comes to GH peptides, and putting dairy in the list as a point of reference:

Gemini said:


SubstanceMechanismOncological Risk ProfileNotable CharacteristicsDairyDietary/Indirect IGF-1Low / BaselineRaises IGF-1 slightly; significant concern mainly for strict oncological diets.SermorelinGHRH AnalogMild RiskShortest half-life; lowest potential for chronic/uncontrolled growth signaling.IpamorelinGHRP (Selective)Mild/Moderate RiskHighly selective for GH; lacks the "hormonal messiness" of older GHRPs.CJC-1295 (No DAC)GHRH AnalogModerate RiskStandard pulse enhancer; more stable than Sermorelin but still pulsatile.TesamorelinGHRH AnalogModerate RiskClinically approved for visceral fat; stronger IGF-1 push than Sermorelin.Tesamorelin + IpamorelinGHRH + GHRP StackElevated RiskSynergistic "turbo" pulse; high peak IGF-1; potent for visceral fat loss.CJC-1295 (No DAC) + IpaGHRH + GHRP StackElevated RiskThe "Classic Stack"; mimics intense natural pulses; overrides natural troughs.GHRP-2 / GHRP-6GHRP (Non-selective)Elevated RiskNon-selective; raises stress hormones (cortisol) and prolactin.HexarelinGHRP (Potent)Elevated RiskStrongest GHRP; highest pulse intensity; potential for rapid desensitization.MK-677 (Ibutamoren)Oral Ghrelin MimeticHigh RiskContinuous GH elevation; potential for 24-hour IGF-1 "over-exposure."CJC-1295 (with DAC)GHRH AnalogHigh RiskCauses "GH bleed"; prevents the body from returning to low-growth baseline.Exogenous HGHDirect HormoneHighest Systemic RiskBypasses feedback loops; direct systemic IGF-1 elevation.IGF-1 LR3Long-Acting IGF-1Extreme / Theoretical DangerPotent inhibitor of apoptosis; persistent signal for cell proliferation.

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Including dairy here strikes me as strange, because it isn't truly a category of its own (even though I get why people often lump it together as one). Hard cheeses give you almost nothing to object to (unless you buy into the saturated fat narrative). On the other hand, a tub of Yoplait amounts to pretty much the same thing as downing a candy bar.

 

[trojanpeptide]

Handy chart... one caveat though: most of the Khavinson peptides on it have almost nothing backing up their function. Several of those extrapolated claims strike me as nonsense, and they trace back to BioLongevity Labs - a plain conflict of interests. I have raised this before, for instance: "FOXO1 is downregulated and NFkB upregulated by KED, aka Vesugen (linked paper)". There is no reason to boost NFkB (=inflammasome); that particular gene modulation is precisely the condition you find in esophageal cancers.

I built a comparable chart of my own, a bare-bones version, and a few contradictions surfaced:

which is how things like GHK-Cu and BPC-157 end up where they do. BPC-157 is the one that needs a lot more work.

As for Kisspeptin, the claim is that it shields you from cancer ...

EDIT:

Spoiler: I put the whole thing through ChatGPT, and a couple of points came out:

1) The PE/PT-22-28 mix-up

What it tells you is that the mechanism assignment in that forum table is likely off, and not only the risk score. The post calls "PT-22-28" a stable VIP / VPAC agonist and then builds a tumor-survival worry out of VIP biology - except PE-22-28 is documented in the literature and in commercial reference material as a spadin-derived TREK-1 blocker, an entirely different signaling class. The upshot: VIP-style cancer logic got attached to the wrong peptide identity. As written, that row does not hold up.

2) BPC-157 is not one-directional "pro-cancer" in the literature

Fair point to press on. In some papers BPC-157 does carry protective / anti-tumor-looking signals - there are reports of it suppressing melanoma cell growth and counteracting VEGF signaling in that model. Against that, the wider repair literature keeps describing BPC-157 as pro-angiogenic, with VEGFR2 upregulation and VEGFR2-Akt-eNOS activation, along with more tube formation and better blood-flow recovery in ischemia models. So the accurate framing is mixed and context-dependent - neither "clearly tumor-promoting" nor "clearly tumor-protective". Critics also note that the anti-cancer case is thin, since no convincing in vivo oncology dataset showing reduced tumor progression or metastasis exists.

Which brings BPC-157 down to a more accurate phrasing:

Attributed effect: a mix of angiogenesis and repair signaling; a possible anti-VEGF effect in a limited set of tumor models, alongside repeated VEGFR2-driven pro-angiogenic findings from non-cancer healing models.

Verifiability: weak to moderate for any sweeping cancer claim.

 

[5byfive]

From a mechanistic standpoint, any peptide that promotes healing or raises GH would plausibly lean toward aiding tumor development. Whether or not you have a history, you can't be sure what might already be present. This area contains plenty of intriguing peptides, but at 50-something, I judge the risk/reward not compelling enough to use them. If you were 25, perhaps the math would look different.

 

[Calm Logic]

tubby said:

Calm Logic said:

When it comes to GH peptides, and putting dairy in the list as a point of reference:

Gemini said:


SubstanceMechanismOncological Risk ProfileNotable CharacteristicsDairyDietary/Indirect IGF-1Low / BaselineRaises IGF-1 slightly; significant concern mainly for strict oncological diets.SermorelinGHRH AnalogMild RiskShortest half-life; lowest potential for chronic/uncontrolled growth signaling.IpamorelinGHRP (Selective)Mild/Moderate RiskHighly selective for GH; lacks the "hormonal messiness" of older GHRPs.CJC-1295 (No DAC)GHRH AnalogModerate RiskStandard pulse enhancer; more stable than Sermorelin but still pulsatile.TesamorelinGHRH AnalogModerate RiskClinically approved for visceral fat; stronger IGF-1 push than Sermorelin.Tesamorelin + IpamorelinGHRH + GHRP StackElevated RiskSynergistic "turbo" pulse; high peak IGF-1; potent for visceral fat loss.CJC-1295 (No DAC) + IpaGHRH + GHRP StackElevated RiskThe "Classic Stack"; mimics intense natural pulses; overrides natural troughs.GHRP-2 / GHRP-6GHRP (Non-selective)Elevated RiskNon-selective; raises stress hormones (cortisol) and prolactin.HexarelinGHRP (Potent)Elevated RiskStrongest GHRP; highest pulse intensity; potential for rapid desensitization.MK-677 (Ibutamoren)Oral Ghrelin MimeticHigh RiskContinuous GH elevation; potential for 24-hour IGF-1 "over-exposure."CJC-1295 (with DAC)GHRH AnalogHigh RiskCauses "GH bleed"; prevents the body from returning to low-growth baseline.Exogenous HGHDirect HormoneHighest Systemic RiskBypasses feedback loops; direct systemic IGF-1 elevation.IGF-1 LR3Long-Acting IGF-1Extreme / Theoretical DangerPotent inhibitor of apoptosis; persistent signal for cell proliferation.

Click to expand...

Including dairy here strikes me as strange, because it isn't truly a category of its own (even though I get why people often lump it together as one). Hard cheeses give you almost nothing to object to (unless you buy into the saturated fat narrative). On the other hand, a tub of Yoplait amounts to pretty much the same thing as downing a candy bar.

When it comes to IGF-1, the items they specifically point to are fluid milk and milk proteins, which raise IGF-1 more than cheese does. Butter shows no real effect on IGF-1.

To be honest, I had forgotten about the other studies on dairy and cancer risk or protection, and that area becomes even more tangled and disputed very fast.

5byfive said:

From a mechanistic standpoint, any peptide that promotes healing or raises GH would plausibly lean toward aiding tumor development. Whether or not you have a history, you can't be sure what might already be present. This area contains plenty of intriguing peptides, but at 50-something, I judge the risk/reward not compelling enough to use them. If you were 25, perhaps the math would look different.

Exactly. The more I consider it, a small boost from sermorelin would be a better fit for me than tesa, at least when used over longer stretches. In my view, sermorelin would catch on more if its price per mg were lower than tesa, though on dosing it does come out cheaper.

 

[Calm Logic]

trojanpeptide said:

Handy chart... one caveat though: most of the Khavinson peptides on it have almost nothing backing up their function. Several of those extrapolated claims strike me as nonsense, and they trace back to BioLongevity Labs - a plain conflict of interests. I have raised this before, for instance: "FOXO1 is downregulated and NFkB upregulated by KED, aka Vesugen (linked paper)". There is no reason to boost NFkB (=inflammasome); that particular gene modulation is precisely the condition you find in esophageal cancers.

I built a comparable chart of my own, a bare-bones version, and a few contradictions surfaced:





View attachment 11631

which is how things like GHK-Cu and BPC-157 end up where they do. BPC-157 is the one that needs a lot more work.

As for Kisspeptin, the claim is that it shields you from cancer ...

EDIT:

Spoiler: I put the whole thing through ChatGPT, and a couple of points came out:

1) The PE/PT-22-28 mix-up

What it tells you is that the mechanism assignment in that forum table is likely off, and not only the risk score. The post calls "PT-22-28" a stable VIP / VPAC agonist and then builds a tumor-survival worry out of VIP biology - except PE-22-28 is documented in the literature and in commercial reference material as a spadin-derived TREK-1 blocker, an entirely different signaling class. The upshot: VIP-style cancer logic got attached to the wrong peptide identity. As written, that row does not hold up.

2) BPC-157 is not one-directional "pro-cancer" in the literature

Fair point to press on. In some papers BPC-157 does carry protective / anti-tumor-looking signals - there are reports of it suppressing melanoma cell growth and counteracting VEGF signaling in that model. Against that, the wider repair literature keeps describing BPC-157 as pro-angiogenic, with VEGFR2 upregulation and VEGFR2-Akt-eNOS activation, along with more tube formation and better blood-flow recovery in ischemia models. So the accurate framing is mixed and context-dependent - neither "clearly tumor-promoting" nor "clearly tumor-protective". Critics also note that the anti-cancer case is thin, since no convincing in vivo oncology dataset showing reduced tumor progression or metastasis exists.

Which brings BPC-157 down to a more accurate phrasing:

Attributed effect: a mix of angiogenesis and repair signaling; a possible anti-VEGF effect in a limited set of tumor models, alongside repeated VEGFR2-driven pro-angiogenic findings from non-cancer healing models.

Verifiability: weak to moderate for any sweeping cancer claim.

Indeed, that mirrors my own thinking. I appreciate you sharing the link. Regarding the Russian peptides, my running joke is to pair them with Russian beet soup, because the soup likely does more for one's health anyway.

trojanpeptide said:

Handy chart... one caveat though: most of the Khavinson peptides on it have almost nothing backing up their function. Several of those extrapolated claims strike me as nonsense, and they trace back to BioLongevity Labs - a plain conflict of interests. I have raised this before, for instance: "FOXO1 is downregulated and NFkB upregulated by KED, aka Vesugen (linked paper)". There is no reason to boost NFkB (=inflammasome); that particular gene modulation is precisely the condition you find in esophageal cancers.

I built a comparable chart of my own, a bare-bones version, and a few contradictions surfaced:





View attachment 11631

which is how things like GHK-Cu and BPC-157 end up where they do. BPC-157 is the one that needs a lot more work.

As for Kisspeptin, the claim is that it shields you from cancer ...

EDIT:

Spoiler: I put the whole thing through ChatGPT, and a couple of points came out:

1) The PE/PT-22-28 mix-up

What it tells you is that the mechanism assignment in that forum table is likely off, and not only the risk score. The post calls "PT-22-28" a stable VIP / VPAC agonist and then builds a tumor-survival worry out of VIP biology - except PE-22-28 is documented in the literature and in commercial reference material as a spadin-derived TREK-1 blocker, an entirely different signaling class. The upshot: VIP-style cancer logic got attached to the wrong peptide identity. As written, that row does not hold up.

2) BPC-157 is not one-directional "pro-cancer" in the literature

Fair point to press on. In some papers BPC-157 does carry protective / anti-tumor-looking signals - there are reports of it suppressing melanoma cell growth and counteracting VEGF signaling in that model. Against that, the wider repair literature keeps describing BPC-157 as pro-angiogenic, with VEGFR2 upregulation and VEGFR2-Akt-eNOS activation, along with more tube formation and better blood-flow recovery in ischemia models. So the accurate framing is mixed and context-dependent - neither "clearly tumor-promoting" nor "clearly tumor-protective". Critics also note that the anti-cancer case is thin, since no convincing in vivo oncology dataset showing reduced tumor progression or metastasis exists.

Which brings BPC-157 down to a more accurate phrasing:

Attributed effect: a mix of angiogenesis and repair signaling; a possible anti-VEGF effect in a limited set of tumor models, alongside repeated VEGFR2-driven pro-angiogenic findings from non-cancer healing models.

Verifiability: weak to moderate for any sweeping cancer claim.

According to the BPC-157 study that Google Gemini pointed to, the FAK-paxillin pathway appears to be involved.

Here is some background on that pathway, which is capable of driving the progression and metastasis of already-present cancer:

https://pmc.ncbi.nlm.nih.gov/articles/PMC5058780/

 

[Loosehead]

5byfive said:

From a mechanistic standpoint, any peptide that promotes healing or raises GH would plausibly lean toward aiding tumor development. Whether or not you have a history, you can't be sure what might already be present. This area contains plenty of intriguing peptides, but at 50-something, I judge the risk/reward not compelling enough to use them. If you were 25, perhaps the math would look different.

I've reached my 50s, and our views on risk versus reward are completely reversed. My thinking is that if something chronic shows up at this point, the most damage it can do is ruin under half of my remaining years. Back when I was a guy in his 20s, I wouldn't even swallow Tylenol because I worried about what it might do down the road. If God lets me reach my 80s, there won't be a thing I won't give a shot.

 

[Calm Logic]

Over at ThePeptideList, there's a bit of low-level, hypothetical worry regarding Epitalon and breast cancer cells studied in vitro:

The September 2025 paper by Al-Dulaimi and colleagues (PMID 40908429, Biogerontology) found that Epitalon activates Alternative Lengthening of Telomeres in two breast cancer cell lines (21NT and BT474). This is a mechanistic in vitro finding, not a human cancer-incidence study. It does not prove Epitalon causes cancer. It does establish that the molecule has measurable activity in cancer cell biology, which is a question every clinician and patient considering Epitalon should discuss before initiating use.

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The research:


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Yet the entire rationale for using Epitalon is anti-aging, which encompasses tumor suppression (in mice, at any rate).