Ivermectin, a cheap, long-established antiparasitic drug, slows many cancer cell types in the laboratory, but this promise remains almost entirely unproven in people. No controlled human trial has shown it treats cancer. Real risks include serious nervous-system harm at high doses and forgoing proven treatment. It is now being tested alongside standard cancer immune-therapy. (Full Review)

Protocol

Dose

0.5–1 mg/kg daily

Off-label repurposing protocols; no validated anticancer dose exists

With Food

With a fatty meal

A fatty meal roughly doubles absorption; consistent fat intake avoids unpredictable levels

Frequency

Once daily

Plasma half-life near 18 hours; some protocols split doses

Time to effect

Time to Benefit

Not established

Efficacy unproven; observational cohort assessed outcomes at six months

Benefits

Low: Broad-spectrum suppression of tumor cell growth

Speculative: Enhanced cancer immunotherapy; reversal of chemotherapy resistance; activity against cancer stem cells

Contraindications

Pregnancy and breastfeeding

Children under ~15 kg

Significant hepatic impairment (Child-Pugh Class B or C)

Active CNS involvement (brain metastases, leptomeningeal disease)

History of Loa loa infection

Known hypersensitivity

Key Interactions

Strong CYP3A4 inhibitors (ketoconazole, itraconazole, ritonavir, clarithromycin, erythromycin)

P-glycoprotein inhibitors (verapamil, quinidine, cyclosporine, ritonavir)

Central nervous system depressants and GABA-active drugs (benzodiazepines, barbiturates, valproate, alcohol)

Warfarin

Grapefruit juice, St. John's Wort, high-fat meals

Risk & Side Effects

High: Central nervous system neurotoxicity

Medium: Gastrointestinal adverse effects; hepatotoxicity; substitution for evidence-based cancer therapy

Low: Ocular and visual disturbances

Speculative: Unknown long-term safety at anticancer doses

Monitoring

Marker	Target	Why
ALT	10–26 U/L	Detects drug-related liver stress early
AST	10–26 U/L	Complements ALT for liver injury
Total bilirubin	0.3–1.0 mg/dL	Flags impaired liver clearance
Complete blood count	Within lab reference range	Baseline for overlapping cancer/therapy effects
Creatinine	0.6–1.1 mg/dL	Baseline organ function before sustained dosing

Cadence: Roughly every 4 weeks for the first few months, then every 3–6 months if continued

Qualitative Assessment

Neurological status: alertness, coordination, absence of tremor or confusion
Vision: any new blurring or visual change
Energy and appetite: general tolerance and gastrointestinal comfort
Overall well-being and objective tumor response on imaging

Ivermectin to Treat Cancer

Protocol

Benefits

Risk & Side Effects

Monitoring

Qualitative Assessment