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Lactaid Fast Act

Generic name: lactase

Brand names: Lactaid, Lactaid Fast Act, Lactaid Ultra, Lac-Dose, Lactrase, Surelac

Last updated November 2, 2026 0 views
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What is Lactaid Fast Act?

Lactaid Fast Act is an enzyme that helps your body break down lactose found in dairy products. If you are lactose intolerant, eating a dairy product can lead to gas, bloating, stomach pain, or diarrhea.

Lactaid Fast Act is a dietary supplement that can help prevent these symptoms for people with lactose intolerance who eat milk or other dairy products.

It is not clear if Lactaid Fast Act is effective for treating any medical condition. The FDA has not approved this product for medicinal use. This medicine should not replace any medication prescribed by your doctor.

Lactaid Fast Act is usually sold as a dietary supplement. There are no regulated manufacturing standards for supplements, and some products on the market have been found to be contaminated with toxic metals or other drugs. To reduce the risk of contamination, dietary supplements should be bought from a trustworthy source.

Lactaid Fast Act may also be used for purposes not mentioned in this product guide.

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How should I take Lactaid Fast Act?

When thinking about using a supplement, ask your doctor for advice. You might also want to talk to someone who specializes in herbal or health supplements.

If you decide to use Lactaid Fast Act, follow the instructions on the package or those given by your doctor, pharmacist, or another healthcare provider. Do not use more of this product than what is recommended on the label.

Take Lactaid Fast Act with the first bite or sip of any dairy product you eat or drink. You can take this medicine every day with every meal and snack that has dairy.

If you eat more dairy products after 30 to 45 minutes, take Lactaid Fast Act again.

Call your doctor if you still have symptoms of lactose intolerance or if your symptoms worsen while using this product.

Store at room temperature away from moisture and heat. Do not refrigerate.

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Warnings

Follow all directions on the label and package.

Use exactly as directed.

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Before taking this medicine

This product may have phenylalanine and could be harmful if you have phenylketonuria (PKU).

Check with a doctor, pharmacist, or other healthcare provider to see if it is safe for you to use this product if you have other medical conditions.

Do not give Lactaid Fast Act to a child younger than 4 years old.

Consult a doctor before using this product if you are pregnant or breastfeeding.

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Lactaid Fast Act side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Less serious side effects may happen more often, and you might not have any at all.

This is not a complete list of side effects, and others may happen. Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

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What happens if I miss a dose?

Take your dose as soon as possible at the start of a meal or snack. Do not take two doses at the same time.

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What happens if I overdose?

An overdose of Lactaid Fast Act is not likely to lead to serious symptoms.

Do not take your dose too early or too late compared to a meal that has dairy, or Lactaid Fast Act may not work as well.

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What other drugs will affect Lactaid Fast Act?

Other drugs may affect Lactaid Fast Act, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all other medicines you use.

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Related medicines

Before you take this medicine: the information on this page is general and may not cover your personal circumstances. Read the label supplied with your medicine and ask a pharmacist or doctor if you are unsure, especially if you are pregnant, breastfeeding, taking other medicines or managing a long-term condition.
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Content is provided for education and is not medical advice. See our medical disclaimer.