Ivermectin Dosage – What You Need to Know

If you’ve been prescribed ivermectin or are considering it for a parasitic infection, the most important question is "how much should I take?" Getting the dose right can mean the difference between a quick recovery and unwanted side effects. Below we break down the basic math, typical schedules, and safety pointers you can use right now.

How to Calculate Your Dose

Ivermectin is usually measured in micrograms per kilogram (µg/kg) of body weight. The most common dosing for skin‑related parasites, such as scabies or lice, is 200 µg/kg taken as a single oral dose. For stronger infections like strongyloidiasis, doctors often give 200 µg/kg once daily for two days.

Here’s a quick way to figure it out:

• Step 1: Weigh yourself in kilograms (kg). If you only know your weight in pounds, divide that number by 2.2.
• Step 2: Multiply your weight by 0.2 (that’s the same as 200 µg/kg).
• Step 3: The result is the amount of ivermectin in milligrams (mg) you need.

Example: If you weigh 70 kg, the calculation is 70 × 0.2 = 14 mg. Most tablets come in 3 mg or 6 mg strengths, so a doctor would likely prescribe two 6 mg tablets (12 mg) plus a half of a 3 mg tablet to hit 14.5 mg. Always follow the exact prescription, because the drug’s safety window is narrow.

Safety Tips & Common Mistakes

Even though ivermectin is on the WHO’s List of Essential Medicines, taking it wrong can cause nausea, dizziness, or, in rare cases, nerve problems. Keep these points in mind:

• Never double the dose to “speed up” treatment. More isn’t better.
• Tell your doctor about any liver disease, pregnancy, or other meds you’re on. Ivermectin can interact with certain drugs, especially those that affect the liver.
• If you miss a dose, take it as soon as you remember unless it’s almost time for the next one. In that case, skip the missed dose – don’t double up.
• Store tablets at room temperature, away from moisture. Bad storage can reduce effectiveness.

For pets, the dosages are completely different, so never use a veterinary product on yourself. Human tablets are calibrated for a specific absorption rate that animal formulas don’t match.

When the prescription is for a short‑term infection, most people finish the course in one or two days. For ongoing conditions like onchocerciasis, the dose may be repeated every 6‑12 months. Your doctor will tell you the exact schedule.

Bottom line: calculate weight‑based dose, follow the prescription, watch for side effects, and keep an open line with your healthcare provider. If anything feels off, call your doctor right away.