Motrin’s active ingredient is ibuprofen, a nonsteroidal anti-inflammatory drug (NSAID) that reduces pain, fever, and inflammation. The standard over-the-counter Motrin IB tablet contains 200 mg of ibuprofen, while prescription-strength Motrin comes in 400 mg, 600 mg, and 800 mg tablets. Beyond ibuprofen itself, every Motrin product contains a supporting cast of inactive ingredients, and specialty versions like Motrin PM and Children’s Motrin have their own distinct formulas.
Active Ingredient: Ibuprofen
Ibuprofen is the only active ingredient in standard Motrin. It works by blocking enzymes called COX-1 and COX-2, which your body uses to produce prostaglandins. Prostaglandins are chemicals that trigger inflammation, pain signaling, and fever. By reducing prostaglandin production, ibuprofen tackles all three at once. It inhibits COX-1 about 2.5 times more strongly than COX-2, which is partly why it’s effective for general pain but also why it can irritate the stomach (COX-1 helps maintain the stomach’s protective lining).
After you swallow a standard ibuprofen tablet, it typically reaches peak levels in your bloodstream within about 1 to 1.25 hours. Its half-life is roughly 2.2 to 2.3 hours, meaning the drug clears your system relatively quickly compared to other pain relievers. That’s why dosing is usually every 4 to 6 hours.
Inactive Ingredients in Motrin IB Tablets
The inactive ingredients don’t treat pain. They hold the tablet together, help it dissolve properly, and give it its characteristic appearance. A standard Motrin IB tablet contains:
- Corn starch and microcrystalline cellulose: fillers that give the tablet its structure
- Croscarmellose sodium: helps the tablet break apart in your stomach so the ibuprofen can absorb
- Stearic acid: a lubricant that keeps the tablet from sticking to manufacturing equipment
- Colloidal silicon dioxide: prevents ingredients from clumping together
- Polyvinyl alcohol, polyethylene glycol, titanium dioxide, and talc: form the smooth outer coating
- FD&C red no. 40 aluminum lake, FD&C yellow no. 6 aluminum lake, and iron oxides: colorants that give the tablet its brown-orange appearance
If you have sensitivities to specific dyes or additives, this list is worth checking. The artificial colorants in particular are something people with dye allergies watch for.
What’s Different in Children’s Motrin
Children’s Motrin is a liquid suspension rather than a tablet, so it needs a completely different set of inactive ingredients to create a syrup that kids will actually swallow. The base formula across all flavors includes glycerin, purified water, polysorbate 80, pregelatinized starch, xanthan gum (a thickener), and anhydrous citric acid for tartness. Sucrose is the sweetener, and sodium benzoate acts as a preservative.
The colorants change by flavor. Bubblegum and fruit flavors use FD&C red no. 40. Grape uses a combination of FD&C blue no. 1, FD&C red no. 40, and D&C red no. 33. Blue raspberry uses FD&C blue no. 1. Parents watching for specific artificial dyes can choose a flavor accordingly, though none of the standard options are dye-free.
What’s in Motrin PM
Motrin PM is the one version that contains two active ingredients. Each caplet has 200 mg of ibuprofen plus 38 mg of diphenhydramine citrate, which is an antihistamine that causes drowsiness. It’s the same type of ingredient found in many over-the-counter sleep aids. The product is designed for people who have pain keeping them awake at night, combining pain relief with a mild sedative effect. If you’re only looking for daytime pain relief, standard Motrin IB is what you want since diphenhydramine will make you drowsy.
Risks Worth Knowing About
Because Motrin is ibuprofen, it carries the same risks as all NSAIDs. The two most significant are gastrointestinal problems and cardiovascular effects.
NSAIDs can cause stomach ulcers, bleeding, and even perforation of the digestive tract. These events happen in roughly 1% of people who take NSAIDs for 3 to 6 months, and in 2 to 4% of those who take them for a full year. The risk climbs the longer you use them. What makes this particularly tricky is that only about one in five people who develop a serious stomach complication had warning symptoms beforehand. Smoking, alcohol use, older age, and a history of ulcers all raise the risk substantially. People with a prior history of peptic ulcers who take NSAIDs have more than 10 times the risk of developing a GI bleed compared to those without that history.
On the cardiovascular side, clinical trials lasting up to three years have shown that NSAIDs increase the risk of heart attack and stroke. This applies to all NSAIDs, not just ibuprofen. The general guidance is to use the lowest effective dose for the shortest time you need it. The maximum daily dose for prescription ibuprofen is 3,200 mg, but over-the-counter Motrin IB labels recommend no more than 1,200 mg per day (three tablets) unless directed otherwise by a doctor.
Motrin vs. Generic Ibuprofen
The active ingredient is identical. A 200 mg Motrin IB tablet delivers the same ibuprofen as a 200 mg store-brand tablet. The differences are purely in the inactive ingredients: the specific binders, coatings, and colorants. These can affect how the tablet looks, tastes, and feels going down, and they matter if you have allergies to particular additives. But in terms of pain-relieving ability, absorption time, and duration of effect, brand-name Motrin and generic ibuprofen are therapeutically equivalent.