What is an LD50 for ibuprofen?
LD50 (median lethal dose) is the dose that kills 50% of a test population in a toxicity study. For ibuprofen, LD50 values vary a lot by species (rat vs. mouse vs. other animals), route of exposure (oral vs. skin/other), and study conditions. Because of that, there isn’t one single “the” LD50 number that applies universally.
Why does “ibuprofen LD50” differ between animals and study routes?
LD50 results change depending on:
- Species (metabolism and sensitivity differ across animals)
- Route of exposure (oral dosing vs. other routes can produce different toxicity profiles)
- Formulation and experimental setup (salt form, fasting state, dosing speed, etc.)
Those variables can lead to meaningfully different LD50 numbers for ibuprofen in different reports.
What should you use LD50 for (and what it is not for)?
LD50 is mainly used in toxicology to compare acute toxicity between substances or to characterize acute risk in nonclinical studies. It is not a reliable predictor of a safe human dose or a specific “lethal dose” for people.
If you meant “How much ibuprofen is dangerous,” what matters instead?
Human risk depends more on clinical factors than on LD50, such as:
- Dose ingested (mg/kg)
- Age/size and health conditions
- Whether the person took other drugs (especially other NSAIDs, alcohol, or certain interacting medicines)
- Timing and access to medical care
If you’re asking because of a potential overdose or exposure, contacting local poison control or emergency services is the right next step.
If this is for research: what exact LD50 value do you want?
If you tell me:
1) the species (rat, mouse, etc.),
2) the route (oral, dermal, etc.),
3) whether you want mg/kg or another unit,
I can narrow to the specific LD50 figure that matches your use case.
Important safety note (if this is a real ingestion)
If someone may have taken too much ibuprofen, call your local poison control center or emergency services right away, especially for children, repeated dosing, or symptoms like vomiting, severe drowsiness, trouble breathing, or seizures.
Sources
I don’t have any provided source documents to cite for specific ibuprofen LD50 numbers.