Cutting pills in half can lead to an improper dosage of a prescription drug, according to a Rutgers State University study published in the September/October Journal of the American Pharmacist Association, Dow Jones/Wall Street Journal reports.

The researchers split 45 tablets with a knife and 45 tablets with a pill splitter and found in both cases that pills split unevenly, making it difficult to measure how much medication the patient would actually receive. It also all but ensured that dosages received would be different each day

Pharmaceutical companies, the American Health Association and the American Pharmacists Association do not advocate pill splitting, but some health insurance companies recommend the practice as a way to reduce prescription drug costs.