How Long It Takes for Naproxen to Work, and Answers to 4 More Naproxen FAQs

Naproxen (Aleve, Naprosyn) is a popular pain-relief medication. You’ve likely seen naproxen tablets and capsules available over the counter (OTC) at your local pharmacy. But it’s also available at higher doses and in different forms with a prescription.

Naproxen is a nonsteroidal anti-inflammatory drug (NSAID). The OTC version is labeled to treat fever and mild-to-moderate pain. Prescription-strength naproxen is FDA approved to treat osteoarthritis and rheumatoid arthritis, among other painful conditions.

If your healthcare team has recommended taking naproxen, you probably have questions about the medication. One of the most common questions people have is, how long does it take for naproxen to work? Below, we’ll answer this and four other common questions about naproxen.

1. How long does it take for naproxen to work?

It usually takes about 30 to 60 minutes for naproxen to start working for mild-to-moderate pain. It may take up to 4 hours to feel the full effects, though. If your symptoms don’t improve within a few hours after taking naproxen, don’t take an extra dose. Taking too much naproxen can be dangerous. Follow the instructions from your prescriber or, if you’re taking the OTC version, the instructions on the label.

For arthritis or inflammatory conditions, it may take about a week for naproxen to start relieving symptoms. But it could take 2 weeks or longer to experience its full anti-inflammatory benefits. If you’re not getting enough relief, check with your prescriber. They can determine if you need a dose change or a different medication.

Keep in mind: Naproxen is meant to treat inflammatory pain, so it may not work as well for other types of pain, such as sciatic nerve pain. If naproxen doesn’t help relieve your pain, speak with your prescriber. They may look into the source of your pain and recommend a different treatment.

2. How long does naproxen stay in your system?

Naproxen can stay in your system for up to 85 hours (about 3.5 days) after you take a dose. But you likely won’t feel the effects for that long.

When taken occasionally, naproxen starts wearing off about 12 hours after you take a dose. That’s why it’s typically recommended to take naproxen every 8 to 12 hours as needed. There’s also an extended-release (ER) version of naproxen that lasts longer — up to 24 hours — so you only need to take a single daily dose. This version, Naproxen ER (Naprelan), is only available by prescription.

With daily use, it’s a little different. If you stop taking daily doses, naproxen’s anti-inflammatory effects will start wearing off in about 4 to 5 days. However, pain relief may wear off sooner.

3. Should you take naproxen with food?

Naproxen can be taken with or without food. But either way, it’s a good idea to take doses with a full glass of water. 

It’s generally recommended to take NSAIDs such as naproxen with food or milk to help reduce stomach irritation. Just keep in mind that taking it with food can also cause it to take longer to work.

Let your prescriber know if you’re experiencing excessive or persistent stomach pain. In severe cases, NSAIDs such as naproxen can cause stomach ulcers or bleeding.

Good to know: Eating certain foods can raise your risk of developing side effects from naproxen. It’s a good idea to avoid taking naproxen with alcohol, coffee, or potassium-rich foods such as avocados.

4. How does naproxen work?

Naproxen works by blocking the production of prostaglandins in the body. Prostaglandins are natural substances that help create pain or swelling when the body is hurt or sick. They’re also responsible for causing fever, widening or narrowing blood vessels, and managing blood clots, among other effects.

Specifically, naproxen blocks cyclooxygenase (COX) proteins, which produce prostaglandins. Blocking COX proteins helps reduce the amount of prostaglandins in the body. And lower levels of prostaglandins means less fever, pain, and inflammation.

5. Does naproxen cause weight gain?

Naproxen doesn’t usually cause weight gain, but some people taking the medication have reported weight changes. If you notice weight gain with naproxen, it’s likely due to water retention. For most people, this appears as swollen ankles or legs. This type of weight gain should be minor and resolve once you stop taking naproxen.

However, water retention from taking naproxen can be more serious for people with heart failure. In people with heart failure, fluid buildup can cause symptoms such as ankle swelling, shortness of breath, and unexplained or rapid weight gain. Naproxen could worsen these symptoms. So your healthcare team may ask you to avoid taking naproxen and other NSAIDs if you have heart failure. 

As a general rule, let your prescriber know if you have unusual or excessive weight changes while taking naproxen.

How to save on naproxen

There are ways to save on naproxen, which is available in both brand-name and generic versions. For example, you could save through GoodRx by having your prescriber write you a prescription for OTC naproxen. Here are some ways you may be able to lower your costs through GoodRx: 

• Save with a GoodRx discount. The price of 60 tablets of OTC naproxen 220 mg may be as low as $14.20 at certain pharmacies with a free GoodRx discount.

• Save with GoodRx Companion. You can access discounted or free naproxen with a GoodRx Companion subscription. Over 200 medications are available for free, with hundreds more for under $10. The program also includes benefits to help you cut your self-pay costs, such as lower prices for online care visits, discounts on dental care, and other health service savings.

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Written by:

Austin Ulrich, PharmD, BCACP

​​Austin Ulrich, PharmD, BCACP, is a board-certified ambulatory care clinical pharmacist. Ulrich’s experience includes direct patient care in hospital and community pharmacies.

Edited by:

Sheila McAdoo, PharmD

Sheila McAdoo, PharmD, is a licensed pharmacist in Virginia and New York. She has worked in the pharmacy industry for 14 years.

Reviewed by:

Christina Aungst, PharmD, MWC

Christina Aungst, PharmD, MWC is a senior pharmacy editor for GoodRx. She began writing for GoodRx Health in 2019.

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