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

When a pill turns brown, a cream separates into oily layers, or a liquid medicine smells like vinegar, it’s not just old-it’s potentially dangerous. Expired drugs don’t always lose potency overnight. Sometimes, they change physically long before the date on the label, and those changes can signal real health risks. You don’t need a lab to spot them. With a little knowledge and careful observation, you can catch warning signs before someone takes a compromised medication.

What Changes to Look For

Expired medications often show three clear signs of degradation: color, odor, and texture. These aren’t random quirks-they’re clues rooted in chemistry and physics. The U.S. Food and Drug Administration (FDA) and World Health Organization (WHO) both confirm that physical changes are among the most common indicators of instability in drugs past their expiration date.

Color shifts are the most frequent. A white tablet turning yellow or brown? That’s not normal aging. Tetracycline antibiotics, for example, commonly darken due to chemical breakdown. Nitroglycerin tablets, which should stay clear or pale yellow, turn deep brown when they degrade. Even clear liquids like eye drops can cloud over or develop a yellow tint. In NASA’s 2011 stability study, 68.3% of expired solid drugs showed visible discoloration.

Odor changes are harder to ignore. If your antibiotic smells rancid, sour, or like wet cardboard, it’s gone bad. Amoxicillin capsules, especially if stored in humid areas, absorb moisture and start to smell musty. Liquid suspensions can develop a fermented odor as bacteria grow. Don’t assume the smell is just from the filler-medications are formulated to be odorless or mildly scented. A strong, off-putting smell means chemical or microbial degradation has occurred.

Texture is the most overlooked sign. A tablet that crumbles when you touch it? That’s friability-too much moisture or heat has broken down the binder. Capsules that feel sticky, clumpy, or swollen? That’s moisture absorption. Creams and ointments that separate into oily and watery layers? That’s phase separation. If you shake a bottle of liquid medicine and particles don’t fully dissolve, or if you see floating specks, that’s particulate formation. These aren’t cosmetic issues-they affect how the drug is absorbed and can cause harm.

How Different Medications Degrade

Not all drugs degrade the same way. The form matters. Solid tablets, liquids, creams, and injectables each follow different breakdown patterns.

Solid oral dosage forms like tablets and capsules are the most common. Tablets may develop dark spots, especially around the edges, or become brittle. Capsules often swell, leak, or harden. Hygroscopic drugs-those that soak up moisture like amoxicillin or aspirin-are especially vulnerable. In one study, amoxicillin capsules stored at high humidity absorbed moisture from 2% to over 15%, causing caking and clumping inside the shell.

Semisolid formulations like hydrocortisone cream, mupirocin ointment, or antifungal gels are prone to phase separation. You’ll see oil rising to the top or water pooling at the bottom. Some creams develop a grainy texture or harden into a waxy lump. Ciprofloxacin ointment, tested in NASA’s space missions, liquefied after 880 days past expiration-even under controlled conditions.

Liquid medications like cough syrups, eye drops, or injectables are the most sensitive. Particles may form, the liquid may cloud, or it may change color. The FDA’s USP <788> standard says non-sterile liquids should have fewer than 6,000 particles per container larger than 10 microns. Once you see visible specks, it’s over the limit. Microbial growth can also occur-especially in multi-dose vials or suspensions without preservatives. If the liquid smells off or looks cloudy, don’t use it.

Why Physical Changes Matter More Than You Think

Some people think if a pill still looks like a pill, it’s fine. That’s dangerous thinking. The National Institute of Justice found that human visual assessment of drug color is only 65.2% accurate compared to instruments. You can miss subtle changes.

Even worse, physical changes don’t always match chemical degradation. Some drugs, like PMZ (phenylbutazone) tablets, lost potency before any color or texture shift occurred. Others, like certain antibiotics, changed color but remained safe and effective. That’s why physical inspection is a screening tool-not a final verdict.

But here’s the key: if you see a physical change, you don’t need to wait for a lab test. The risk isn’t worth it. The WHO estimates that 10.5% of expired drugs show physical changes that affect safety. That’s more than 1 in 10. In hospital settings, 37.6% of expired drug incidents involved overlooked discoloration in light-sensitive meds like nitroglycerin. One hospital kept using expired morphine sulfate with fine crystals-mistaking them for normal sediment-and caused 14 patient adverse events.

How to Inspect Medications Properly

You don’t need special tools, but you do need a system.

1. Use good lighting. Inspect under natural daylight or a 500-lux lamp. Avoid dim or yellow lights.
2. Use a white background. Place pills or creams on a clean white paper or plate. This makes color shifts easier to spot.
3. Compare to new ones. If you have an unexpired bottle of the same drug, compare side by side. Look for differences in shade, texture, or clarity.
4. Smell everything. Open capsules and sniff. Smell liquids before shaking. If it smells wrong, it is wrong.
5. Check texture. Gently press a tablet between your fingers. Does it crumble? Does a cream feel grainy or oily? Does a liquid leave residue when shaken?
6. Document anything odd. Write down what you saw: “light brown discoloration on tablet edges,” “cream separated into two layers,” “liquid smells like vinegar.” Photos help, especially if you’re unsure.

Many pharmacies and research labs use the Colored Dot System-color-coded stickers on expiration dates-to remind staff to check monthly. You can do something similar at home. Use a permanent marker to write the expiration date on the outside of the bottle. Check it every 3 months.

What to Do When You Spot a Problem

If you see any of these changes, stop using the medication immediately. Don’t flush it down the toilet or toss it in the trash. Take it to a pharmacy with a drug take-back program. Many pharmacies accept expired or unwanted medications for safe disposal.

If you’re unsure, call your pharmacist. They can look up the drug’s stability profile and tell you whether the change is common or alarming. For example, some antibiotics naturally darken slightly over time-but only within a specific range. A pharmacist can tell you if it’s within normal limits.

Never take a drug that looks, smells, or feels off-even if it’s just a few days past the expiration date. The risk of reduced effectiveness or harmful reactions isn’t worth it.

What Doesn’t Count as Degradation

Not every change means the drug is bad. Some drugs are designed to look different.

• White tablets with faint lines or specks? Those are often harmless excipients (fillers) that settle.
• Some liquids are cloudy by design, like suspensions of antibiotics for children.
• Creams may thicken slightly in cold weather but return to normal at room temperature.

When in doubt, compare to the manufacturer’s reference images. The FDA’s Drug Expiration Database includes photos of common degradation patterns. If you’re still unsure, consult a pharmacist.

Storage Matters More Than You Realize

Most people store medicines in the bathroom-hot, humid, and full of steam. That’s the worst place. Heat and moisture speed up degradation. Studies show that temperatures above 25°C (77°F) can accelerate physical changes by 2.3 times.

Store medications in a cool, dry place-like a bedroom drawer or kitchen cabinet away from the stove. Avoid leaving pills in the car or in direct sunlight. Keep them in their original bottles with the child-resistant cap on. Don’t transfer them to pill organizers unless you’re using them within a week.

Future Trends: Technology Is Changing the Game

While visual inspection remains the most accessible method, especially in low-resource areas, technology is catching up. Portable Raman spectrometers and smartphone-based color analyzers are becoming affordable. Pfizer’s Visual Stability AI, currently in trials, can predict drug degradation from microscopic texture images with 94.3% accuracy.

By 2025, the European Medicines Agency may require spectrophotometric verification for injectables. But for now, your eyes, nose, and fingers are your best tools. No app replaces a careful look.

Final Rule: When in Doubt, Throw It Out

Medications aren’t like food. You can’t taste them to check if they’re spoiled. There’s no second chance if a degraded drug causes an allergic reaction, reduces effectiveness, or triggers side effects. The cost of a new bottle is nothing compared to the cost of a bad reaction.

If you see a color change, an odd smell, or a strange texture-don’t hesitate. Dispose of it safely and get a new one. Your body doesn’t care if the expiration date was yesterday or last year. It only cares if the medicine works-and if it’s safe to take.