Breastfeeding mothers should be cautious about taking creatine, according to gynecologist and obstetrician Nubia Fontes, who said there is not yet enough evidence to determine how the supplement changes the concentration of breast milk or what effects it could have on a baby.
Fontes made the comments in an interview with CNN Brasil, addressing a growing trend of postpartum women taking creatine and other fitness supplements as they try to combine motherhood with a healthy lifestyle.
She said creatine and related compounds are part of the body's normal physiology, but there is not enough evidence to safely establish how much a supplement changes its concentration in breast milk or what effects additional exposure could have on a nursing infant. Because of that, she said she does not consider it appropriate to recommend the supplement indiscriminately during breastfeeding.
Fontes stressed that creatine use is not prohibited for breastfeeding women, but it should be moderate and only taken after medical guidance.
Creatine's rise in popularity
Creatine has grown from a supplement associated almost exclusively with athletes into one of the most widely consumed supplements in the world. The trend has been fueled partly by the fitness scene on social media, where influencers such as Virginia Fonseca and Carol Borba have shared content about creatine and other exercise-related supplements, reaching audiences of mothers who follow them.
In Brazil, the growth is also visible among women, who now account for one in four purchases of the product, according to a survey by Soldiers Insights released in the first quarter of 2026.
Fontes said the ideal approach is not to start taking creatine simply because it is popular in gyms or on social media. She said breastfeeding women should talk to their obstetrician and, when necessary, a pediatrician and a nutritionist, since doctors need to assess the postpartum stage, diet, exercise habits, kidney function, medication use, other supplements, and the health of both mother and baby.
Can creatine bring benefits?
Outside the specific context of breastfeeding, creatine has been studied for its role in rapid energy production and for possible benefits related to strength, physical performance, and preserving or building muscle mass when combined with appropriate training.
Fontes said these effects draw interest from postpartum women looking to regain strength and fitness. However, she said those potential benefits need to be weighed carefully by mothers.
She said a possible advantage for the mother does not remove the need to assess safety for the baby during breastfeeding. In the postpartum period, she said, doctors also need to individually consider diet, the amount of sleep possible at that stage, obstetric recovery, return to exercise, and the woman's clinical condition before considering supplementation.
Staying healthy after childbirth
Fontes said maintaining a healthy routine after pregnancy does not mean quickly getting back to a pre-pregnancy body. She said the priority should be proper nutrition, hydration, medical follow-up, and a gradual return to physical activity.
She explained that the body has gone through pregnancy and childbirth and is now dealing with the demands of breastfeeding and caring for a newborn. She concluded that postpartum recovery is a process, and that health at this stage has much more to do with giving the body the conditions it needs to recover than with meeting aesthetic or performance goals.
