It sounds simple enough: Cut your pills in half to cut your prescription costs in half. The do-it-yourself practice of pill splitting is one that many doctors and health plans support. It’s a way to counter rising drug prices and encourage people to take their medications if they’re likely to skip doses and refills because of high costs. And those who have trouble swallowing medicine might find a smaller pill easier to manage.

How it works

Your doctor will prescribe a higher dose of medication, often double. (Sometimes the higher dose is the same price as the lower dose.) At home, you cut the pills in half and take half each day, ending up with two doses for the price of one.

But deep discounts aren’t guaranteed, so first ask your pharmacist what you’ll save, advises Barbara Young, editor of consumer-medication information for the American Society of HealthSystem Pharmacists.

Note that the Food and Drug Administration has called pill splitting a “risky practice” and doesn’t encourage it unless a drug’s package insert specifically says it has been approved for splitting. But Consumer Reports’ medical advisers say it’s safe if you follow the guidelines below.

Four smart steps

Get your doctor’s okay first. According to a 2015 poll by Consumer Reports Best Buy Drugs, 8 percent of consumers trying to save money on medications admitted to cutting their pills in half without a doctor’s or pharmacist’s approval. Many drugs — notably, most cholesterol-lowering statins and drugs that treat high blood pressure and depression — can be split without losing effectiveness or causing a negative health impact, but it can be dangerous to divide others.

Your doctor may have other reasons to warn you about splitting pills. It’s not advised if you have dementia or memory problems, for example, or if you have a condition — such as arthritis, hand tremors or poor eyesight — that makes it difficult to do so.

Split only pills that can be divided accurately. Most time-released, long-acting and combination drugs shouldn’t be split because it’s difficult to make sure that you’ll get the proper amount of the active ingredient in each half.

Pills that are coated to protect your stomach, such as enteric-coated aspirin and ibuprofen, shouldn’t be split, either. Those with a hard coating and capsules of any kind are best swallowed whole because they can easily crumble, leak or crack into pieces. Chemotherapy drugs and those that require stable daily blood levels, such as anti-seizure medication, birth control pills and blood thinners, should never be split.

Use the right tool. Get a pill splitter, a small device that cuts with a sharp blade or by pressing pills between two opposing edges. Studies have found that pill splitters come closest to dividing medication into precise halves. They’re usually inexpensive and widely available at pharmacies and large discount stores. Your health insurer may even send you one free.

Never use a knife, scissors, a razor blade, a box cutter or any other sharp tool for the job. They can create unequal parts, and using them may increase the likelihood of an injury. Replace a splitter when it no longer divides pills easily and accurately.

Split pills one at a time. Some pills deteriorate when exposed to air, heat or moisture after being split. So cut a pill just before you take it, then take the other half as your next dose. That helps ensure that you compensate for any deviation in size. And split pills in half — not into smaller portions, such as quarters. When in doubt, ask your doctor or pharmacist to show you how to do it properly.

Copyright 2016. Consumers Union of United States Inc.

For further guidance, go to www.ConsumerReports.org/Health, where more detailed information, including CR’s ratings of prescription drugs, treatments, hospitals and healthy-living products, is available to subscribers.