Peps to avoid if worried about cancer/tumor growth

[GrandmaJ]

I found this list of peptides to avoid if you have past history of cancer cells or tumors but it seems incomplete based on some things I have read here. I like to think I am of average intelligence but so much of this is beyond my grasp of science and research.

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

Does anyone have a complete list they keep of peps they are avoiding? I want to add KPV for some hip and knee issues. I just ordered P21 trying to get in front of a family history of memory issues. Also considering SS31, TA1 and Cartalax but still afraid to pull the trigger even after weeks of trying to research the risks.

 

[Calm Logic]

Playing with AI today, PT-22-28 was a surprise for theoretical cancer risk. But PT-22-28 may prevent precancerious DNA inflammation, which could be "protective against cancers of the digestive tract (colon/gastric/liver)."

GHK basic (without copper) was low risk compared to GHK-Cu. But both may be protective against cancer, especially colon cancer, by "resetting metastatic gene expression."

Risk Assessment for Commonly Discussed Peptides & Substances

Peptide / Substance	Cancer/Growth Risk	Immunological Risk	Contraindications	Primary Mechanism	Findings & Related Studies
HGH (Somatropin)	High	High	Active malignancy, retinopathy.	Full 191-AA Protein.	Growth Signaling: Directly promotes systemic proliferation. High ADA risk.
Tesamorelin / CJC / Sermorelin	High	Moderate-High	Malignancy history, pregnancy.	GHRH / IGF-1 Axis.	Growth Signaling: Directly increases IGF-1. PMID: 20472.
PT-22-28 (Stable VIP)	High (Theoretical)	Moderate	Active malignancy, hypotension.	Potent VPAC Agonist.	Survival Signaling: Long-acting VIP; fuels tumor survival via VPAC receptors.
TB-4 / TB-500	High	Moderate-High	Suspected malignancy, sterile abscesses.	Angiogenesis / Actin.	Tumor Support: Promotes metastasis and blood supply. PMID: 23270513.
BPC-157 / Dihexa	High	Low	GI, vascular, or c-Met tumors.	VEGF / c-Met Activation.	Angiogenic Switch: Potent drivers of oncogenic growth. PMID: 21030672.
Melanotan II (MT2)	High (Specific)	Moderate	Melanoma history, atypical nevi.	Melanocortin Agonist.	Melanocyte Risk: Non-selective; aggressive mole darkening and dysplasia risk.
Test-C / hCG	Moderate-High	Moderate	Prostate/Breast cancer, high RBC.	Androgen / LH Mimetic.	Hormonal Fuel: High-octane fuel for sensitive tumors. PMID: 37326322.
Enclomiphene	Moderate	Low	DVT history, visual disturbances.	SERM (Pituitary).	Feedback Drive: Indirectly raises T/E2; requires prostate monitoring.
Ipamorelin / MT1	Moderate	Moderate	Malignancy, hypersensitivity.	GHS / Selective MC1R.	Growth/Tanning: Selective profiles but still stimulate growth pathways.
VIP / LL-37 / Kiss-10	Moderate	Moderate	Neuroendocrine/Hormone cancers.	Receptor Agonists.	Mixed Signaling: Pro-survival for tumors in specific environments.
Cerebrolysin	Moderate	High	Porcine allergy, epilepsy.	Porcine Derived.	Immunological Risk: Potential for autoimmune reactions to foreign proteins.
GHK-Cu	Moderate (Dual)	Moderate	Active malignancy, copper allergy.	Copper / VEGF.	Angiogenesis: Copper complex promotes tumor blood supply.
AOD-9604 / Tesofensine	Low-Moderate	Low	Hypertension, cardiovascular disease.	hGH Frag / Monoamine.	Metabolic Focus: Low proliferative risk; primary concerns are cardiovascular.
GHK (Copper-Free)	Low-Moderate	Low	Known hypersensitivity.	Gene Modulation.	Oncostatic: Reverses metastatic gene expression (Broad C-Map).
PT-141 / Semax / Selank	Low	Low	Hypertension, psych crisis.	Neuromodulation.	Safe Profile: Targeted effects with no known proliferative drive.
ARA-290	Low	Low	Hypersensitivity.	Innate Repair.	Non-Proliferative: Anti-inflammatory that avoids EPO-style growth.
GLP-1s / Cagrilintide	Low (Protective)	Low	MTC history, pancreatitis.	Metabolic Incretins.	Oncostatic Findings: 36% colorectal cancer risk reduction. PMID: 37952131.
TA-1 (Thymosin Alpha-1)	Low (Protective)	High	Organ transplant.	Immune Modulator.	Surveillance: Enhances tumor detection. High anaphylaxis risk.
Epithalon / Pinealon	Low (Protective)	Low	Hypersensitivity.	Telomere Stabilization.	Oncostatic: Reduces tumor incidence in long-term models.
Testagen / Prostamax	Low (Protective)	Low	Hypersensitivity.	Reproductive Bioreg.	Functional Repair: Normalizes protein synthesis in target glands.
Pancreagen / Ovagen	Low (Protective)	Low	Hypersensitivity.	Organ Bioregulators.	Normalization: Repairs protein synthesis in pancreas/liver.
Bronchogen / Cortegen	Low (Protective)	Low	Hypersensitivity.	Organ Bioregulators.	Functional Recovery: Targets lungs and cerebral cortex.
Vesugen / Cardiogen	Low (Protective)	Low	Hypersensitivity.	Vascular Bioreg.	Endothelial Support: Repairs heart/vessels without driving growth.
Cartalax / DSIP / KPV	Low (Protective)	Low	Hypersensitivity.	Targeted Repair.	Safe/Anti-Inflam: Localized repair and NF-κB inhibition.
MOTS-c / Glutathione	Low	High	Sulfur allergy, DAMPs.	Metabolic/Antiox.	Allergy/Abscess: High risk for anaphylaxis and SubQ/IM sterile abscesses.
SS-31 / NAD+	Low	Low	Acute metabolic crisis.	Mitochondrial Health.	Protective: Supports ATP efficiency; no known growth signaling risk.
Carnitine / B12	Low	Moderate	Cobalt allergy.	Nutrient Support.	Localized Risk: Abscess risk from high-volume IM injections.

No real cancer risk with GLPs, mostly protective:

GLP-1 Cancer Risk: 2026 Consensus

Cancer Type	Risk Level	Key 2026 Finding	Primary Mechanism
Colorectal	Protective	36% risk reduction (ASCO).	Lowers insulin/IGF-1 and GI inflammation.
Pancreatic	Neutral	No causal link in human meta-analysis.	Improved glycemic control outweighs early fears.
Liver (HCC)	Protective	Prevents NASH/NAFLD progression.	Directly reduces hepatic fat and oxidative stress.
Breast/Ovary	Protective	Reduced hormone-driven tumors.	Weight loss lowers peripheral estrogen (aromatase).
Kidney/Renal	Protective	Reduced oxidative DNA damage.	Improves hemodynamics; lowers renal stress.
Thyroid (MTC)	Monitoring	Rodent-only; human data remains clear.	Warning for MEN2/MTC history only.

For the peptide LL-37:

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.

 

[Calm Logic]

Regarding GH peptides, with dairy listed for comparison:

Substance	Mechanism	Oncological Risk Profile	Notable Characteristics
Dairy	Dietary/Indirect IGF-1	Low / Baseline	Raises IGF-1 slightly; significant concern mainly for strict oncological diets.
Sermorelin	GHRH Analog	Mild Risk	Shortest half-life; lowest potential for chronic/uncontrolled growth signaling.
Ipamorelin	GHRP (Selective)	Mild/Moderate Risk	Highly selective for GH; lacks the "hormonal messiness" of older GHRPs.
CJC-1295 (No DAC)	GHRH Analog	Moderate Risk	Standard pulse enhancer; more stable than Sermorelin but still pulsatile.
Tesamorelin	GHRH Analog	Moderate Risk	Clinically approved for visceral fat; stronger IGF-1 push than Sermorelin.
Tesamorelin + Ipamorelin	GHRH + GHRP Stack	Elevated Risk	Synergistic "turbo" pulse; high peak IGF-1; potent for visceral fat loss.
CJC-1295 (No DAC) + Ipa	GHRH + GHRP Stack	Elevated Risk	The "Classic Stack"; mimics intense natural pulses; overrides natural troughs.
GHRP-2 / GHRP-6	GHRP (Non-selective)	Elevated Risk	Non-selective; raises stress hormones (cortisol) and prolactin.
Hexarelin	GHRP (Potent)	Elevated Risk	Strongest GHRP; highest pulse intensity; potential for rapid desensitization.
MK-677 (Ibutamoren)	Oral Ghrelin Mimetic	High Risk	Continuous GH elevation; potential for 24-hour IGF-1 "over-exposure."
CJC-1295 (with DAC)	GHRH Analog	High Risk	Causes "GH bleed"; prevents the body from returning to low-growth baseline.
Exogenous HGH	Direct Hormone	Highest Systemic Risk	Bypasses feedback loops; direct systemic IGF-1 elevation.
IGF-1 LR3	Long-Acting IGF-1	Extreme / Theoretical Danger	Potent inhibitor of apoptosis; persistent signal for cell proliferation.

 

[tubby]

Regarding GH peptides, with dairy listed for comparison:

Dairy is an odd one to include since it's not really a proper category (although I understand it often gets treated as a category). There's very little to dislike about hard cheeses (unless one buys into the saturated fat story). Meanwhile, that container of Yoplait is essentially the equivalent of eating a candy bar.

 

[trojanpeptide]

Nice table... but, remember that a lot of those Khavinson peptides have little to no evidence of function. Some of those extrapolated claims I find ludicrous, and came from BioLongevity Labs, which is a conflict of interests. For example, I've pointed out before that "FOXO1 is downregulated and NFkB upregulated by KED, aka Vesugen (linked paper)". There is no reason to increase NFkB (=inflammasome), this gene modulation is the exact condition one finds in esophageal cancers.

I also made a similar table, simpler, but it showed some conflict:

such as in BPC-157 and GHK-Cu showing up as they do. BPC-157 requires more research.

Kisspeptin suppose to protect you from cancer ...

EDIT:

Spoiler: I ran all the data through ChatGPT, couple things:

1) What that PE/PT-22-28 issue means


It means the mechanism assignment in that forum table is probably wrong, not just the risk score. The post labels “PT-22-28” as a stable VIP / VPAC agonist and then derives a tumor-survival concern from VIP biology, but PE-22-28 is described in the literature and commercial reference material as a spadin-derived TREK-1 blocker, which is a completely different signaling class. So the problem is: they may have attached VIP-style cancer logic to the wrong peptide identity. That makes that row low-confidence as written.


2) BPC-157 is not one-way “pro-cancer” in the literature


You are right to push on that. BPC-157 does have protective / anti-tumor-looking signals in some papers, including reports that it inhibited melanoma cell growth and counteracted VEGF signaling in that model. But the broader repair literature also repeatedly describes BPC-157 as pro-angiogenic, with VEGFR2 upregulation and VEGFR2-Akt-eNOS activation, plus increased tube formation and improved blood-flow recovery in ischemia models. So the honest framing is mixed and context-dependent, not “clearly tumor-promoting” and not “clearly tumor-protective” either. There is also criticism that the anti-cancer case is weak because there is still no convincing in vivo oncology dataset showing reduced tumor progression or metastasis.


So for BPC-157, the best corrected wording is closer to:


Attributed effect: mixed angiogenesis / repair signaling; possible anti-VEGF effect in limited tumor models, but also repeated VEGFR2-driven pro-angiogenic findings in non-cancer healing models.
Verifiability: low-to-moderate for any broad cancer claim.

 

[5byfive]

Mechanisticly, it would seem any of the healing or GH boosting peps would tend to a risk of helping tumor growth. History or not, you never know what's there. There are a lot of interesting peps in this space, but as someone in my 50's I feel the risk/reward isn't strong enough to do it. Maybe if you're 25, the calculation would be different.

 

[Calm Logic]

Dairy is an odd one to include since it's not really a proper category (although I understand it often gets treated as a category). There's very little to dislike about hard cheeses (unless one buys into the saturated fat story). Meanwhile, that container of Yoplait is essentially the equivalent of eating a candy bar.

For IGF-1, when they single anything out, it's fluid milk and milk proteins as increasing IGF-1 more than cheese. Butter no real effect on IGF-1.

Honestly, I forgot about the other research on dairy for cancer risk/protection, which does get even more complicated and controversial very quickly.

Mechanisticly, it would seem any of the healing or GH boosting peps would tend to a risk of helping tumor growth. History or not, you never know what's there.

Exactly. Like the more I think about it, a little boost from sermorelin would make more sense for me than using tesa, at least for longer periods of time. I think sermorelin would be more popular if the price per mg was cheaper than tesa, but it is cheaper as far as dosing.

 

[Calm Logic]

remember that a lot of those Khavinson peptides have little to no evidence of function. Some of those extrapolated claims I find ludicrous, and came from BioLongevity Labs, which is a conflict of interests.

Yes, my thoughts exactly. Thanks for the link. My joke with the Russian peptides is to have Russian beet soup with them, since the soup is probably more effective for health.

2) BPC-157 is not one-way “pro-cancer” in the literature

You are right to push on that. BPC-157 does have protective / anti-tumor-looking signals in some papers, including reports that it inhibited melanoma cell growth and counteracted VEGF signaling in that model. But the broader repair literature also repeatedly describes BPC-157 as pro-angiogenic, with VEGFR2 upregulation and VEGFR2-Akt-eNOS activation, plus increased tube formation and improved blood-flow recovery in ischemia models. So the honest framing is mixed and context-dependent, not “clearly tumor-promoting” and not “clearly tumor-protective” either. There is also criticism that the anti-cancer case is weak because there is still no convincing in vivo oncology dataset showing reduced tumor progression or metastasis.


So for BPC-157, the best corrected wording is closer to:


Attributed effect: mixed angiogenesis / repair signaling; possible anti-VEGF effect in limited tumor models, but also repeated VEGFR2-driven pro-angiogenic findings in non-cancer healing models.
Verifiability: low-to-moderate for any broad cancer claim.
[/SPOILER]

The BPC-157 study referenced by Google Gemini suggests involvement of the FAK-paxillin pathway.

Some info on that pathway, which can help progress and metastasize existing cancer:

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

 

[Loosehead]

Mechanisticly, it would seem any of the healing or GH boosting peps would tend to a risk of helping tumor growth. History or not, you never know what's there. There are a lot of interesting peps in this space, but as someone in my 50's I feel the risk/reward isn't strong enough to do it. Maybe if you're 25, the calculation would be different.

I am in my fifties and we have opposite risk/ reward theories. I feel if I obtain a long term issue now, the worse I can do is mess up less than half of my life. As a guy in my 20's I refused to even take Tylenol for the fear of long term effects. God willing, I make to my 80's, I will try anything and everything.

 

[Calm Logic]

Some mild, theoretical concern at ThePeptideList about Epitalon and breast cancer cells in the lab:

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.

The study:

Epitalon increases telomere length in human cell lines through telomerase upregulation or ALT activity - PubMed

Epitalon, a naturally occurring tetrapeptide, is known for its anti-aging effects on mammalian cells. This happens through the induction of telomerase enzyme activity, resulting in the extension of telomere length. A strong link exists between telomere length and aging-related diseases...

pubmed.ncbi.nlm.nih.gov

But the whole point of taking Epitalon is for anti-aging, including tumor suppression (at least in mice).