Vitals Knowledge Vault

Ivermectin

6 min read

Ivermectin

TL;DR

Ivermectin is an FDA-approved antiparasitic macrocyclic lactone (single 150–200 μg/kg oral dose) with documented in vitro anticancer activity across multiple cancer models, including colorectal cancer (CRC) cell lines. There are zero published human clinical trials for ivermectin in colorectal cancer. The dose required to match in vitro anticancer concentrations in humans would be approximately 2–20× the maximum approved antiparasitic dose. The maximum safe human dose tested (~2 mg/kg) achieves free plasma concentrations ~200-fold below the median in vitro IC50. Ivermectin is not a treatment for colon cancer and should not delay or replace evidence-based care.

Why it matters for Vitals

Vitals members will encounter ivermectin-colon-cancer claims on social media, often alongside politically charged narratives from the COVID-ivermectin era. These claims are entirely preclinical. The dose gap between what kills CRC cells in a dish and what can safely be given to humans is approximately 200-fold. Coaches need to:

  • Clearly explain why in vitro activity ≠ human evidence
  • Prevent treatment delay harm if a member has a CRC diagnosis
  • Identify political contamination of the scientific discourse
  • Provide accurate safety and interaction information for members already using ivermectin off-label

Key Facts

FactDetail
Approved indicationAntiparasitic: onchocerciasis, strongyloidiasis, scabies, lymphatic filariasis
Standard dose150–200 μg/kg oral, single dose
Cmax at standard dose~30–55 ng/mL (~60 nM); 93% protein-bound → ~4.2 nM free
Maximum safe human dose tested~2 mg/kg (~14× standard); free plasma ~20–25 nM
In vitro CRC IC50 range0.8–5 μM (800–5,000 nM) — ~200× higher than achievable free drug
MetabolismCYP3A4; P-glycoprotein substrate and inhibitor
Human oncology trialsZero registered or published for colorectal cancer
Active oncology trialNCT05318469: ivermectin + balstilimab in triple-negative breast cancer (no results published)
Evidence grade for CRCEntirely preclinical (in vitro + animal models); no human data

Mechanism Summary

Ivermectin has multiple mechanistically distinct anticancer targets, all demonstrated in vitro or in rodent models:

  1. P-gp / MDR1 reversal via EGFR/ERK/Akt/NF-κB (HIGH evidence; CRC cells primary model) — direct EGFR binding confirmed biophysically; reverses drug resistance in HCT-8 CRC xenografts at 2 mg/kg i.p.
  2. WNT-TCF pathway inhibition (HIGH evidence; CRC) — suppresses AXIN2/LGR5/ASCL2; reduces CRC spheroids up to 73% at 0.1–5 μM
  3. PAK1 kinase degradation → Akt/mTOR suppression (HIGH evidence; multi-cancer including CRC) — induces PAK1 ubiquitination; downstream mTOR pathway validated
  4. Mitochondrial apoptosis / ROS induction (HIGH evidence; multi-cancer including CRC) — complex I inhibition; ROS scavengers abrogate cytotoxicity; cancer cells 3–5× more sensitive than normal cells
  5. Cancer stem cell (CSC) inhibition (HIGH evidence; CRC spheroid data) — preferentially kills CD44+/CD24- CSC population; Nanog/Oct4/Sox2 reduced 50–80% at 0.5 μM
  6. Anti-angiogenesis (MODERATE evidence; glioblastoma/HBMEC models; no CRC xenograft data) — mitochondrial dysfunction in endothelial cells at 10 μM
  7. Immunogenic cell death (ICD) via P2X4/P2X7 (MODERATE evidence; CT26 murine CRC cells respond) — ATP/HMGB1 release; pyroptosis
  8. SIN3A/B epigenetic modulation (MODERATE evidence; breast cancer; CRC not studied) — EMT reversal via PAH2 domain binding
  9. YAP1/Hippo inhibition (LOW evidence; gastric cancer primary; CRC not studied) — nuclear YAP1 reduction

Note: Literature claiming STAT3 inhibition for ivermectin in CRC is NOT supported. STAT1 is activated (upregulated), not STAT3 inhibited. Any STAT3 claim for CRC should be treated as unverified.

What the Current Evidence Suggests

Established

  • Ivermectin kills CRC cell lines (DLD1, Ls174T, HCT-8, CC14, CC36, HT29) at μM concentrations in vitro
  • Key mechanisms are biophysically validated (direct EGFR binding by Octet RED96; NMR-confirmed SIN3A/B PAH2 binding)
  • Ivermectin reverses P-gp-mediated drug resistance in CRC xenografts (2 mg/kg i.p. + vincristine)
  • WNT pathway suppression is robust and CRC-relevant (~80% of CRC has APC mutation → WNT constitutive activation)
  • CSC-inhibition data in CRC spheroid models is mechanistically strong

NOT Established

  • Human efficacy for any cancer indication
  • Safe anticancer dose range in cancer patients
  • Combination safety or synergy with any CRC chemotherapy (FOLFOX, FOLFIRI, CAPOX, bevacizumab)
  • Biomarker or molecular subtype predicting response
  • Whether the dose gap can be bridged by any formulation, route, or schedule

The Dose Gap (Critical)

The median in vitro IC50 across cancer types is ~5 μM. Maximum achievable free plasma at 2 mg/kg (highest safe human dose tested) is ~20–25 nM. ~200-fold disconnect. The claim that “clinically achievable concentrations are sufficient” is pharmacokinetically disputed and unproven. Achieving tumoricidal concentrations would require doses 2–20× above the approved maximum, with no human safety data at those doses.

Likely Wearable / Vitals Relevance

Low for direct wearable signal. At antiparasitic doses, ivermectin does not produce a characterized biometric signature in consumer wearables. At investigational anticancer doses, the biometric effects are entirely uncharacterized.

Potential coaching intersections:

  • HRV/sleep: Not expected to produce a reliable wearable signal at approved doses; CNS toxicity at high doses (tremor, dizziness) could affect HRV and sleep metrics
  • Body composition: No effect expected
  • Recovery/readiness: No characterized effect
  • Detection: No validated detection model for ivermectin use in wearables; not a detection priority for Vitals

For members using ivermectin off-label: monitor for neurotoxicity signs (tremor, confusion, ataxia), especially with CYP3A4/P-gp inhibitor co-administration.

Risks and Uncertainty

Direct Risks

  • Neurotoxicity at high doses (P-gp saturation at BBB → CNS accumulation): tremor, confusion, ataxia, seizures in susceptible genotypes (ABCB1 polymorphism)
  • Treatment delay harm: Members with CRC who delay or replace evidence-based treatment (surgery, chemotherapy, immunotherapy) for ivermectin suffer documented worse outcomes
  • Drug interactions: CYP3A4 inhibitors (ketoconazole, ritonavir, clarithromycin) may increase ivermectin levels 2–3×; P-gp substrate chemotherapeutics (irinotecan) may have altered exposure — no clinical data for any CRC chemotherapy
  • Hepatotoxicity: rare at standard doses; significance at anticancer doses unknown

Uncertainty

  • No Phase I safety data in cancer patients at anticancer doses
  • No long-term (multi-cycle) safety data at high doses
  • No PK data in cancer patients with organ dysfunction
  • No data on immune-related adverse events with PD-1/PD-L1 combinations
  • P-gp polymorphic variation impact on high-dose safety uncharacterized

Red Flags for Vitals Coaches

  • Any claim that ivermectin “cures” colon cancer
  • FLT3 targeting claims for CRC (FLT3 is not meaningfully expressed in CRC; validated in AML)
  • DOH+ protocol promotion (zero peer-reviewed evidence; alternative medicine channels only)
  • Social media testimonials without pathological or imaging confirmation
  • Recommendation to delay or replace standard-of-care CRC treatment

Best Stack Context

Not applicable as an anticancer agent. For Vitals context:

  • Stack relevance: None as a cancer treatment. Ivermectin remains a standard antiparasitic.
  • Off-label use context: Some members may use high-dose ivermectin (5–15 mg/day or more) sourced from veterinary formulations. This is explicitly outside the evidence base and carries unknown safety risks. Coaches should flag this.
  • Research monitoring: The NCT05318469 TNBC trial is the only active oncology trial; results, if published, would be worth monitoring for any signal that could eventually justify a CRC trial.
  • Safety tier: Per Peptide Oncology Safety Tiers, ivermectin has no Phase I human oncology evidence. Cannot be recommended as anticancer therapy. For members with cancer history: do not recommend as cancer treatment; flag treatment delay risk.

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