MiraLAX Onset Time: When Will You Feel Relief?

If you have occasional constipation, you’ve probably heard of MiraLAX. This popular over-the-counter laxative offers gentle, reliable relief without the cramping or urgency that other options might cause. This article will answer 10 common questions about MiraLAX usage, from how it works to when to expect relief. 

1. How Does MiraLAX Work?

MiraLAX is an over-the-counter osmotic laxative containing polyethylene glycol 3350 (PEG 3350). Its uses include treating occasional constipation and as a bowel prep before procedures like a colonoscopy.

MiraLAX works by drawing water into the colon, softening stools, and making them easier to pass. It comes as a sugar-free, gluten-free powder you mix with any beverage.

2. What is MiraLAX Used For?

• Occasional constipation relief

• Bowel prep before a colonoscopy

MiraLAX treats occasional constipation, which is a temporary condition that factors like diet, travel, or changes in routine can cause. Do not use it to treat chronic constipation, a persistent condition that may require medical attention. If your constipation lasts more than 7 days, consult your healthcare provider. 

3. What is the recommended MiraLAX dose?

• 17 grams once daily for adults and children 17 and older for occasional constipation

• 238 grams for colonoscopy prep

If you’re taking MiraLAX for occasional constipation relief, use the bottle cap or single-dose packets to measure the correct dose of 17 grams. 

Stir the powder in 4 to 8 fluid ounces of any liquid (hot, cold, or room temperature) until it dissolves and drink it immediately. 

Do not take more than one cap or packet of MiraLAX in a 24-hour period. Taking more than the recommended dose may not work faster and can put you at risk of serious adverse effects.

Mix a 238-gram dose of polyethylene glycol 3350 for colonoscopy prep in 64 ounces of clear liquid such as water, Crystal Light, or Gatorade. Do not use red, orange, or purple liquids. Refrigerate the mixture if desired. 

4. How Does MiraLAX Relieve Constipation?

MiraLAX is an osmotic laxative that draws water into the colon to soften the stool and increase stool volume, making it easier to pass. 

5. When Can You Expect Relief After Taking MiraLAX?

MiraLAX usually produces a bowel movement in 1 to 3 days when taken to relieve occasional constipation.  

If you are taking MiraLAX for colonoscopy bowel prep, bowel movements usually begin within a few hours of drinking the first dose, although it can take longer if you’re severely constipated or dehydrated. Be sure to drink plenty of water before and after taking MiraLax.

6. How Long Does MiraLAX Relief Last? 

Miralax effects last about a day and may take 2 to 3 days to disappear from your system entirely. 

The laxative gradually travels through your digestive system and is eliminated from your body with stool. Therefore, you need to take MiraLAX every day for it to continue working. 

However, you should not use MiraLAX for long-term relief from chronic constipation without a doctor’s approval, as it can lead to dependence, diarrhea, dehydration, and electrolyte imbalance. 

While MiraLAX is perfectly fine for occasional constipation, consider lifestyle changes such as a fiber-rich diet and regular exercise to reduce the risk of constipation. 

7. What Are the Side Effects of MiraLax?

MiraLax is generally well-tolerated, causing fewer side effects than other laxatives. 

The most common side effects of MiraLax include:

• Bloating

• Cramping

• Gas

• Watery stools

• Urgency 

In rare cases, MiraLax can cause serious side effects. Seek emergency medical care if you experience any of the following:

• Signs of allergic reaction, such as hives, rash, difficulty breathing, vomiting, or swelling of the face. 

• Severe diarrhea, which can lead to dehydration.

• Bowel obstruction, which is a blockage of the intestine. Call your doctor if you do not have a bowel movement after 3 days or need to take MiraLAX for more than a week. 

8. How Does MiraLax Compare to Other Laxatives?

MiraLAX is a gentle laxative that provides relief in 1 to 3 days from occasional constipation without harsh side effects (stomach pain, cramping, and sudden urgency).

Other laxative options, such as fiber supplements, mineral oil laxatives, or stimulant laxatives like Senokot or Dulcolax tablets, can provide faster relief from constipation (typically 6 to 12 hours), or suppositories, which work in under 30 minutes. However, these options are not as gentle as MiraLAX and can cause side effects such as severe cramping, bloating, urgency, diarrhea, and stomach pain.

9. How to Get the Best Results From MiraLAX?

• Take MiraLAX at the first signs of constipation. 

• Measure the recommended dose correctly. 

• Eat a fiber-rich diet.

• Before taking PEG 3350 (MiraLAX), tell your doctor about your other medications and medical conditions. 

• Do not use expired MiraLAX powder.

• Keep all medications out of reach of children and pets.

10. Is Miralax safe for kids? 

While MiraLAX is not currently FDA-approved for children younger than 17, studies have shown no health risks. Talk to your doctor before giving MiraLAX to your child, as they may recommend a different dosage or treatment method.