List of Best-Selling Over-the-Counter (OTC) Drugs

Over-the-counter (OTC) drugs are a huge business for the pharmaceutical industry in the United States, accounting for over $35 billion in gross revenues in 2018. Despite having lower per-unit costs, OTC drugs often surpass prescription drugs in terms of annual sales.

OTC drugs include those you can buy off the drugstore, grocery store, or convenience store shelf as well as those dispensed by a healthcare provider without a prescription.

OTC drugs do not include dietary supplements, such as vitamins, herbal remedies, and "nutriceuticals," all of which are loosely regulated by the U.S. Food and Drug Administration (FDA).

OTC Regulations

OTC drugs are those that the FDA deems are safe for use without the need for healthcare provider oversight. This doesn't mean the drugs are without concern or appropriate for all groups. The definition of an OTC drug is often ill-defined and contentious, with advocates alternately calling for some drugs to be sold without a prescription and others to be pulled off drugstore shelves as unsafe for OTC use.

This is due in part to the way that the OTC drugs are regulated in the United States. If a new drug is introduced with a unique molecule or mechanism of action, the FDA will require the manufacturer to submit a New Drug Application (NDA) before it can be sold interstate.

On the other hand, if the drug is simply a new brand of a commonly used drug or one made with commonly used ingredients, it may be exempt from an NDA regulation and allowed to enter the market under the "generally regarded as safe and effective" (GRAS/E) classification.

Behind-the-Counter Drugs

Where FDA classifications become confusing is when certain OTC drugs are subject to restrictions. Examples include human (non-analog) insulin, emergency contraceptives, and pseudoephedrine.

Restricted OTC products are commonly referred to as behind-the-counter (BTC) drugs, a classification first approved by the U.S. Congress in 1984 when regulators decided to allow the sale of ibuprofen over the counter.

The reasons for the restrictions are varied. The restriction of pseudoephedrine, for example, was imposed to reduce it from being converted into the street drug crystal methamphetamine. The Plan B One-Step emergency contraceptive, by contrast, was restricted because consumers confused it for the abortion pill.

Other restrictions are far less clear, in part because individual states can impose their own restrictions on how an FDA-approved OTC drug is sold. Oregon, for example, passed laws requiring a prescription for any amount of pseudoephedrine, while other states have imposed restrictions on the sale of syringes, codeine, and other OTC products.

Top-Selling OTC Drugs

According to the Washington, D.C.-based non-profit Consumer Healthcare Protection Association, the top-selling OTC drug categories in 2018 were:

A Word From Verywell

Because OTC drugs are sold in the same way as soap, vitamins, and bandages, many people consider them to be inherently safe. Clearly, this is a mistake. Any drug has the potential for harm if misused. As a rule of thumb, remember that even the most familiar OTC product:

• Has the potential for overuse and overdose
• May interact with other drugs, including alcohol
• May undermine the effectiveness of other drugs you are taking
• May cause allergy in some
• May not be appropriate for children, pregnant women, people with liver or kidney problems

In truth, the risk may be minimal to nil. Nevertheless, it is important to read the product label before using an OTC product and to advise your healthcare provider about any and all drugs you are taking, including dietary supplements and recreational drugs.

If you do not understand the product label, speak with your pharmacist. That is what a pharmacist is there for.