Can You Take Creatine While Breastfeeding? What We Know (and Don't)

Getting back to the gym after having a baby can feel great, and creatine is one of the most popular supplements for strength training. If you used it before pregnancy, it’s natural to wonder whether you can pick it up again while you’re nursing.

This is one of those questions where the honest answer is “we don’t know yet.” Below is what the research does and doesn’t show, why experts currently lean toward caution, and how to support your training without it. For general rules on medicines and supplements, see our hub on what’s safe while breastfeeding.

What is creatine?

Creatine is a compound your body makes and also gets from foods like meat and fish. It helps muscles produce quick bursts of energy. As a supplement, it’s usually sold as creatine monohydrate powder.

According to the NIH Office of Dietary Supplements, creatine is one of the most thoroughly studied sports supplements. It mainly helps with repeated short, intense efforts such as weightlifting and sprinting, and seems to do little for endurance exercise. In healthy adults, few safety concerns have been reported at typical doses, and the main documented side effect is weight gain from water retention.

None of that research looked at breastfeeding mothers, though.

Is creatine safe while breastfeeding?

Here’s what LactMed, the National Library of Medicine’s drugs and lactation database, says:

• Creatine is a normal part of breast milk. It supplies about 9% of a baby’s daily needs. Levels are highest in colostrum and drop over the first two weeks after birth.
• Supplements haven’t been measured in milk. No one has tested how much creatine reaches milk after a mother takes a supplement.
• There may be an effect on lab tests. Creatine turns into creatinine in the body. LactMed notes it may raise a baby’s blood creatinine, which could make kidney function tests harder to interpret.
• The recommendation: until more data are available, it’s probably best to avoid creatine supplementation unless it’s prescribed by a healthcare professional.

LactMed also mentions that some researchers have speculated that creatine supplements in nursing mothers might help babies with rare creatine deficiency disorders, but no studies have tested this.

LactMed also found no published information on creatine levels in breastfed babies, on effects in breastfed babies or on effects on milk production. In short, every box that would normally guide a decision is empty.

So the cautious advice isn’t because creatine is known to harm babies. It’s because there are no data at all, and the one possible effect that has been described involves your baby’s kidney blood tests.

Why “natural” doesn’t settle the question

It’s tempting to think that because creatine is already in breast milk, a bit more can’t hurt. But a supplement can deliver far more creatine than your diet, and nobody knows whether that changes milk levels a little, a lot or not at all. The same is true of many supplements: being found in the body naturally doesn’t tell you what a concentrated dose will do.

There’s also the supplement itself to consider. The FDA does not review or approve the safety of dietary supplements before they’re sold. What’s on the label, and how pure the product is, depends on the manufacturer.

If you’re still considering it

If creatine matters to you, for example for competitive training, take these steps:

1. Talk to your doctor or pharmacist first. Bring the product so they can see the ingredients and the dose on the label. Don’t go above the label’s directions.
2. Mention your baby’s age and health. Experts are generally more cautious with newborns, premature babies and babies with kidney or other health conditions.
3. Tell your pediatrician if you take it, especially before any blood tests for your baby.
4. Choose a single-ingredient product. Pre-workout blends often add stimulants. If you also drink coffee, our guide to caffeine while breastfeeding explains why totals matter.
5. Look for independent quality testing on the label, while remembering that a quality seal checks what’s in the product, not whether it’s safe during breastfeeding.

Ways to support training without creatine

You can still build strength and energy while breastfeeding:

• Eat enough. Breastfeeding uses extra energy, and training on too little food can leave you running on empty. Our breastfeeding calorie calculator gives you a personal estimate.
• Prioritize protein at each meal, from foods like eggs, dairy, fish, meat, beans and tofu. Easy ideas are in our list of breastfeeding snacks.
• Drink to thirst. The American College of Obstetricians and Gynecologists suggests keeping water handy and sipping during workouts.
• Feed or pump before you exercise. ACOG says this helps you avoid discomfort from full breasts. A supportive sports bra helps too.
• Build back gradually. ACOG recommends working up to at least 150 minutes of moderate aerobic activity a week after having a baby, which you can split into short sessions. Check with your provider before you start, especially after a cesarean birth or complications.

When to call a doctor or lactation consultant

Stop the supplement and call your doctor, pediatrician or an IBCLC if:

• your baby seems unusually fussy, sleepy or unwell,
• your baby has fewer wet diapers or isn’t gaining weight as expected,
• you notice a drop in your milk supply, or
• you have swelling, stomach problems or other side effects.

If you’re not sure how much milk your baby should be getting, our breast milk intake calculator can help you check, and our breastfeeding support page lists where to get help.