How to Recognize Changes in Color, Odor, or Texture in Expired Drugs

Every year, millions of people take expired medications without realizing the risks. You might find an old bottle of antibiotics in your medicine cabinet, or a bottle of painkillers past its printed date. It’s easy to assume, "It’s probably still fine." But expired drugs don’t just lose potency-they can physically change in ways that make them unsafe. The key is knowing what to look for: color, odor, and texture. These aren’t just signs of age-they’re red flags that tell you the medicine may no longer be safe to use.

What Happens to Medications After They Expire?

Expiration dates aren’t arbitrary. They’re based on real stability testing done by manufacturers under controlled conditions. The U.S. Food and Drug Administration (FDA) requires these tests to ensure drugs remain safe and effective until the date printed on the label. After that, chemical breakdowns begin. Some ingredients degrade into new compounds. Others absorb moisture, react with light, or separate into layers. The result? Physical changes you can see, smell, or feel.

According to NASA’s 2011 study of pharmaceuticals in space, discoloration was the most common sign of degradation-seen in nearly 70% of expired solid dosage forms. Tetracycline antibiotics, for example, turn from white to yellow or brown as they break down. This isn’t just cosmetic. That color change signals chemical reactions that can make the drug less effective-or even toxic.

Color Changes: The Most Obvious Warning Sign

Color is the easiest thing to check. But it’s also the most misunderstood. Not every shade shift means danger-but many do.

• White tablets turning yellow, brown, or gray? That’s a red flag. Tetracycline, doxycycline, and aspirin are especially prone to this.
• Capsules or tablets with dark spots or streaks? That’s often mold or chemical separation.
• Clear liquids like eye drops or injectables turning cloudy or yellow? That’s a major warning. Nitroglycerin, for example, turns from clear to yellow-brown when it degrades-losing its ability to treat chest pain.
• Creams or ointments with unusual discoloration, like orange or green tints? That’s rare, but when it happens, it’s almost always due to microbial contamination.

Human eyes aren’t perfect. Studies show we only catch about 65% of color changes without tools. That’s why institutions like the University of Wisconsin’s RARC program use Munsell color charts-standardized color references-to compare pills against known samples. If your pill looks off, even slightly, don’t guess. Compare it to a fresh one or check the FDA’s Drug Expiration Database for reference images.

Odor: Smell Can Save Your Life

Medications shouldn’t smell bad. If they do, something’s wrong.

Most pills and capsules are odorless. If you open a bottle and smell vinegar, ammonia, or something musty, stop. That’s not normal. It usually means the active ingredient has broken down into acidic or volatile byproducts. Amoxicillin capsules, for instance, can develop a sour or rancid odor when moisture gets in and causes the powder inside to ferment.

Liquids and creams are even more sensitive. A fishy smell in eye drops? That’s bacterial growth. A sharp, chemical odor in a topical gel? Could be solvent evaporation or decomposition. In forensic labs, odor is one of the first indicators used to flag suspect drugs. If it smells wrong, it is wrong.

Texture: When Medicine Feels Off

Texture changes are harder to notice-but just as dangerous.

Tablets should be hard and uniform. If they crumble easily, feel sticky, or have a chalky residue on your fingers, they’ve absorbed moisture. That’s bad. Moisture speeds up chemical breakdown and can make pills unsafe.

Capsules? They should be smooth and intact. If the contents inside are clumped together like wet sand, or if the capsule shell is cracked or swollen, discard it. Hygroscopic drugs like amoxicillin or iron supplements are especially vulnerable.

Creams and ointments should be smooth and consistent. If you see oil floating on top, water pooling at the bottom, or the texture has turned grainy or rubbery, that’s phase separation. Clotrimazole cream and mupirocin ointment have been shown to separate after just 880 days past expiration. The separated layers don’t deliver the right dose-and may irritate skin or eyes.

Liquids should be clear and free of particles. If you see floating specks, cloudiness, or sediment, don’t use it. USP standards say sterile liquids must have fewer than 6,000 particles per container. You don’t need a lab to spot large chunks or cloudy haze. If it looks like it has dirt in it, it’s unsafe.

When Physical Changes Don’t Mean Danger (And When They Do)

Not every change is a disaster. Some drugs naturally darken over time. For example, some iron supplements turn slightly darker as they oxidize-but still remain safe. But here’s the catch: you can’t tell the difference without a reference.

That’s why comparison matters. Always keep a current, unopened bottle of the same medication for reference. If you can’t, check the manufacturer’s website or the FDA’s database. Many pharmaceutical companies provide images of what their products look like when they degrade.

And remember: physical changes don’t always match chemical degradation. Some drugs lose potency before they change color. Others look fine but contain harmful breakdown products. That’s why the FDA warns: if a drug looks, smells, or feels wrong, don’t risk it-even if it’s just one month past the date.

How to Check Your Medications at Home

You don’t need a lab to spot dangerous changes. Here’s how to do it right:

1. Take the medication out of its container and place it on a clean, white surface under bright, natural light.
2. Look closely: Is the color uniform? Are there spots, streaks, or discoloration?
3. Smell it: Does it smell like anything unusual-vinegar, mold, chemicals?
4. Touch it: If it’s a tablet, gently press it. Does it crumble? Is it sticky? If it’s a cream, rub a small amount between your fingers. Is it smooth, or is it grainy, oily, or separated?
5. Compare: If you have a fresh bottle, compare side by side. If not, look up the drug online for expected appearance.

For high-risk medications-like insulin, epinephrine, or heart medications-don’t rely on visual checks alone. If in doubt, throw it out. These drugs can fail silently, and the consequences are life-threatening.

What to Do With Expired or Degraded Medications

Never flush most medications down the toilet or throw them in the trash. The FDA recommends drug take-back programs. Many pharmacies and police stations offer free disposal bins. If none are available, mix the medication with coffee grounds or cat litter in a sealed container before tossing it. This prevents accidental ingestion by children or pets.

And don’t keep old meds “just in case.” The risk of using degraded drugs far outweighs the convenience. A 2019 FDA report found that a hospital kept using expired morphine that had developed crystals-mistaking them for normal. Fourteen patients suffered adverse reactions.

Future of Drug Safety: Tools Are Coming

While visual checks are still the most accessible method, technology is catching up. Portable Raman spectrometers can now identify drug composition in seconds with 87% accuracy. Pfizer’s Visual Stability AI, currently in testing, can predict expiration by analyzing microscopic texture changes with 94% accuracy.

But until those tools are in every home, your eyes, nose, and fingers are your best defense. The World Health Organization still calls simple visual inspection the most practical way to spot degraded medicines in low-resource areas. That’s because the signs are real, visible, and consistent.

You don’t need to be a pharmacist to protect yourself. You just need to pay attention.

Final Advice: When in Doubt, Throw It Out

There’s no such thing as a harmless expired drug. The risks-reduced effectiveness, unexpected side effects, or even poisoning-are real. Your body doesn’t know the difference between a pill that’s one day past its date and one that’s five years old. It only responds to what’s in it.

Check your medicine cabinet every six months. Look at each bottle. Smell it. Feel it. Compare it. If anything seems off, don’t take it. Your health isn’t worth the gamble.