Lactase enzyme supplements are an over-the-counter prevention tool for those who suffer from lactose intolerance. Lactose intolerance means that your body's deficient in naturally occurring lactase, the enzyme that breaks down lactose, the natural sugar in milk. The supplement helps your body break down lactose from milk and foods containing milk. For most people, lactase enzyme supplements shouldn't cause any side effects if taken correctly. But if you take them at the wrong time or are allergic to them, problems can arise.
If you're lactose intolerant, you need to take lactase enzymes as soon as you consume anything with lactose, such as milk, cheese, ice cream and yogurt. Additionally, if you're still eating a lactose-rich food 20 to 45 minutes after taking that first bite and initial dose, you might need to take another lactase enzyme supplement, Drugs.com reports. If you take the supplement after eating or skip a second dose, you could experience gastrointestinal problems, such as cramping, bloating and diarrhea, as your body works to digest that lactose on its own.
While interactions with prescription drugs haven't been reported, certain medications may negatively interact with lactase enzymes, because the pharmaceutical industry is ever changing. Lactase supplement does have the potential to affect how certain drugs work. Check with your doctor or pharmacist to see if any interactions exist between the prescriptions you're taking and lactase enzymes.
You could have hives, rashes or itchy skin if you're allergic to any of the ingredients in a lactase enzyme supplement. Swelling of the face, mouth, lips and tongue, difficulty breathing and chest tightness are other signs of an allergy. If you're severely allergic, these symptoms can start as soon as you touch the pill. But if you have a more mild reaction, you might not have skin irritations until a while after taking the supplement.
Lactase enzymes aren't a guaranteed fix-it tool. You could still have problems consuming milk-containing foods. Usually, symptoms of lactose intolerance set in within a couple hours of eating dairy, the National Digestive Diseases Information Clearinghouse reports. But if you continue to have abdominal problems hours afterward, even if you took the lactase enzyme properly, you'll need to visit your physician. While lactase enzyme reactions aren't common, they can happen.