What a Stromectol purchase is actually counting
On the DailyMed Stromectol listing (setid 681888c9-af79-4b7d-ae80-c3f4f6f1effd, revised September 2024), Stromectol is ivermectin for oral use, supplied only as a 3 mg tablet. Approved uses printed there are intestinal strongyloidiasis from Strongyloides stercoralis, the nondisseminated form, and onchocerciasis from Onchocerca volvulus.
A licensed pharmacy may dispense brand Stromectol or another manufacturer's 3 mg ivermectin tablet for those same uses. Imprint and package differ. The active ingredient does not. Topical ivermectin for rosacea is a different product. So is any veterinary formulation.
Before a card number goes in, the FDA guide to buying medicines safely from an online pharmacy asks for a real prescription, a US address and phone, a pharmacist you can reach, and a pharmacy license in your state. That checklist, worked as a fill path, lives on the compound page. This guide is the kilogram arithmetic those tablets are built for.
The 3 mg tablet is unscored. Product characteristics list score as none, size about 6 mm, color white, shape round. People sometimes want to snap it for an in-between weight. The charts below count whole tablets until a row says to calculate.
Strongyloidiasis bands near 200 mcg per kilogram
| Body weight | 3 mg tablets | Amount |
|---|---|---|
| 15-24 kg | 1 | 3 mg |
| 25-35 kg | 2 | 6 mg |
| 36-50 kg | 3 | 9 mg |
| 51-65 kg | 4 | 12 mg |
| 66-79 kg | 5 | 15 mg |
| 80 kg and above | Calculate 200 mcg/kg | Prescriber converts |
The strongyloidiasis dosage is a single oral dose meant to provide about 200 mcg of ivermectin per kilogram. Tablets go down on an empty stomach with water. Follow-up stool tests are how clearance is documented. In general, further doses are not required once eradication is confirmed.
Activity against Strongyloides stercoralis is limited to intestinal stages. Disseminated disease is outside this indication. In immunocompromised patients, including people with HIV, repeated courses are sometimes required, and the single-dose row is only the starting guideline. That repeat problem is spelled out on the evidence review.
Read the band your kilogram falls in. Do not average it with the onchocerciasis table underneath.
Onchocerciasis bands near 150 mcg per kilogram
| Body weight | 3 mg tablets | Amount |
|---|---|---|
| 15-25 kg | 1 | 3 mg |
| 26-44 kg | 2 | 6 mg |
| 45-64 kg | 3 | 9 mg |
| 65-84 kg | 4 | 12 mg |
| 85 kg and above | Calculate 150 mcg/kg | Prescriber converts |
Onchocerciasis uses a single oral dose meant to provide about 150 mcg per kilogram, again on an empty stomach with water. The drug hits tissue microfilariae of Onchocerca volvulus. It has no activity against the adult worm. Adults sit in subcutaneous nodules and keep producing larvae, so follow-up and retreatment are usual.
In mass campaigns the common interval is 12 months. For an individual patient, retreatment may be considered at intervals as short as 3 months. The same evening stays a single dose.
A 60 kg adult lands on different rows. Strongyloidiasis, 51-65 kg, is 4 tablets (12 mg), and 60 times 200 mcg is 12 mg exactly. Onchocerciasis, 45-64 kg, is 3 tablets (9 mg), and 60 times 150 mcg is 9 mg exactly. One kilogram, one worm name, one count. Mixing the charts is a one-tablet miss at that weight.
The cut-points themselves differ. At 25 kg, strongyloidiasis is already the 2-tablet band (25-35 kg) while onchocerciasis is still the 1-tablet band (15-25 kg). At 70 kg the strongyloidiasis band is 5 tablets (15 mg) even though 70 times 200 mcg is 14 mg. The onchocerciasis band at that weight is 4 tablets (12 mg) even though 70 times 150 mcg is 10.5 mg. Use the printed band. Raw multiplication is what the chart already did, until the row says calculate.
At 80 kg and above for strongyloidiasis, and at 85 kg and above for onchocerciasis, the row stops printing a fixed tablet count. 80 kg times 200 mcg is 16 mg, which is not a whole number of 3 mg tablets. The prescriber chooses the count. A kitchen round-up is not on the chart.
Empty stomach, the four-hour peak, and a fatty meal
Patients are told to take Stromectol on an empty stomach with water. After a 12 mg fasting dose in healthy volunteers, about 165 mcg/kg on average, the major component peaked near 4 hours. Plasma half-life is about 18 hours. Almost all of the dose leaves in feces over about 12 days, and under 1 percent leaves in urine.
A separate volunteer study gave 30 mg after a high-fat meal (48.6 g of fat) and saw about a 2.5-fold rise in bioavailability compared with 30 mg fasting. That jump is why the worm doses stay fasted. Take the prescribed count with water on an empty stomach.
Half a day of waiting is normal. Peak near 4 hours and a half-life near 18 hours means the first quiet hour still sits before the peak. Strongyloidiasis usually stays a single dose once stools confirm clearance. Onchocerciasis retreatment is measured in months.
Ivermectin is metabolized mainly by CYP3A4. At concentrations that matter clinically it did not meaningfully block CYP3A4, CYP2D6, CYP2C9, CYP1A2, or CYP2E1 in the microsome work described with the tablet. Post-marketing reports have rarely described a higher INR when ivermectin was taken with warfarin. Anyone on warfarin should tell the prescriber before the first tablet.
Where the charts stop
Safety and effectiveness have not been established in patients weighing less than 15 kg. The first row of each table is 15 kg. An unscored 3 mg tablet is a poor tool for inventing a smaller dose for a lighter child.
Ivermectin should not be used during pregnancy, because safety in pregnancy has not been established. Animal studies found cleft palate at doses that were also toxic to the pregnant animal. Stromectol does pass into human milk in low concentrations. Treatment of someone who intends to breast-feed is a balance the prescriber makes between delay for the mother and possible risk for the newborn.
People with onchocerciasis who also carry a heavy Loa loa infection can develop a serious or fatal brain illness, sometimes on its own and sometimes after a drug that kills microfilariae. The warning lists neck and back pain, red eye, conjunctival bleeding, trouble breathing, incontinence, trouble walking, confusion, seizures, stupor, or coma. It has been seen very rarely after ivermectin. Anyone with significant time in Loa loa regions of West or Central Africa needs that exposure named before a tablet is chosen, whatever brought them to the clinic.
Hypersensitivity to any component of the tablet is a contraindication. Neurotoxicity has also been reported without onchocerciasis and without Loa loa: sleepiness, stupor, coma, confusion, and death. Those reactions have generally been managed with supportive care and by stopping the drug. Extra tablets because the first hour felt quiet are a bad experiment.
Mites, veterinary products, and virus requests
Scabies is not one of the two Stromectol indications. When a clinic still uses oral ivermectin for mites, that is an off-label decision and it still means the human 3 mg tablet under a prescriber. The bands on this page are the worm charts only. They are not a mite calendar.
Veterinary ivermectin, whether a paste, a pour-on, or an injectable, is formulated for livestock. The overdosage section records what has happened after people swallowed, inhaled, injected, or spilled those products on skin: rash, swelling, headache, dizziness, weakness, nausea, vomiting, diarrhea, and in some reports seizures, ataxia, abdominal pain, or trouble breathing. There is no syringe-to-tablet conversion here.
COVID-19 is not a Stromectol indication, and the clinical-studies tables do not contain a virus arm. A virus dose is not hiding in the kilogram bands. Trial numbers that do exist, for the two worms, are on the evidence review. How the tablet got its name is on the history note.
Questions people ask next
Is Stromectol the same as ivermectin? Stromectol is the US brand of ivermectin 3 mg tablets on DailyMed. A generic 3 mg tablet from a licensed pharmacy is the same active ingredient for the same approved uses. Packaging and imprint change.
Why is 60 kg either 4 tablets or 3? Four tablets (12 mg) is the 51-65 kg strongyloidiasis band, about 200 mcg/kg. Three tablets (9 mg) is the 45-64 kg onchocerciasis band, about 150 mcg/kg. The prescription has to name the worm.
What happens at 80 kg? The strongyloidiasis row says to calculate 200 mcg/kg instead of printing a fixed count. 80 kg times 200 mcg is 16 mg, which does not divide cleanly into 3 mg tablets. The prescriber sets the count. The onchocerciasis calculate-row starts at 85 kg.
Pounds or kilograms? Both charts are kilograms. 60 kg is about 132 pounds. Convert a US scale before choosing a band.
Can the tablet be split? It is unscored. The charts count whole 3 mg tablets until a row says to calculate.
With food or without? Empty stomach and water for both worm doses. A high-fat meal increased exposure about 2.5-fold after 30 mg in volunteers.
Is there a COVID count on this chart? No. The indications are intestinal strongyloidiasis and onchocerciasis.
Where do I check the seller? The compound page walks the prescription and the state-licensed pharmacy. Dollar titles in ads are not invoices, and this guide does not print a price.