What’s the Scoop on Protein Supplements during Pregnancy and Breastfeeding?

Do you enjoy protein shakes, adding protein powder to your smoothies, or using pre-workout mixes with protein? My friend, Emily, is currently in her first trimester and loves getting extra protein. Before she got pregnant, she started power lifting, which also came with extra protein supplementation. Once she got pregnant, Emily asked me, like so many others in her position, if she could continue her protein supplementation during pregnancy and when breastfeeding.

With any pregnancy, there is a 3% chance of developing a birth defect.  So I looked into protein supplementation to see if it changes the risk for birth defects, side effects during breastfeeding, or any other issues. That way, Emily could make a well-informed decision for her health and the health of her family.

Many of these protein products contain types of protein that are also found in everyday foods and even in breast milk. Everyone needs a certain amount of protein every day as a part of a balanced diet. However, there are certain reasons why someone might have a specific daily protein intake goal. Like Emily, many people are interested in having more protein to build muscle. There are other health conditions, like phenylketonuria (PKU), that affect how much protein you should get in your diet. Ultimately, it is very important for you to review your personal daily protein intake goals with your healthcare team to make sure your health is supported.

Not every protein supplement has been well studied, so information on using them during pregnancy or breastfeeding is limited. In addition, many protein powders and drinks also include other ingredients, such as added vitamins or herbal products. For more information on herbal products, check out our fact sheet on here:  https://mothertobaby.org/fact-sheets/herbal-products-pregnancy/.

Supplements are regulated differently than prescription drugs. Even though the United States Food and Drug Administration (FDA) regulates supplements, the FDA doesn’t check every product for safety or effectiveness before it goes on the shelf. This means some protein powders might contain some unknown or unlisted ingredients.

So before adding that extra scoop of protein powder, take some time to figure out if protein supplementation is right for you.

How Much Protein Do You Need?

How much protein you need depends on different factors, such as age, activity level, and health. Some proteins have a daily recommended dietary allowance (RDA). The RDA depends on a person’s weight. You, most likely, get some amount of protein from your diet naturally. It’s important to take your diet into consideration when trying to figure out how much protein you should be having. Because there are so many things to consider, it’s recommended to talk with your healthcare team to make sure you are meeting your nutritional needs. Getting the right amount of protein for you is not expected to increase the risk for issues during pregnancy or side effects during breastfeeding.

What are the typical amino acids in protein supplements?

Most protein powders contain many amino acids. Amino acids are the building blocks of protein. The list below may not include everything that might be found in your protein powder. Since not every amino acid has an RDA, here is a list of the known amino acids with an RDA. It’s always a good idea to double check with your healthcare team on what your specific protein intake goals are.

  • Cysteine & Methionine*
    • RDA during pregnancy: 25 mg/kg

    • RDA during breastfeeding: 26 mg/kg

  • Isoleucine
    • RDA during pregnancy: 25 mg/kg

    • RDA during breastfeeding: 30 mg/kg

  • Leucine
    • RDA during pregnancy: 56 mg/kg

    • RDA during breastfeeding: 62 mg/kg

  • Lysine

    • RDA for adults: 12 mg/kg

  • Threonine
    • RDA during pregnancy: 26 mg/kg

    • RDA during breastfeeding: 30 mg/kg

  • Tryptophan

    • RDA for adults: 3.5 mg/kg

  • Valine
    • RDA for pregnancy: 31 mg/kg

    • RDA for breastfeeding: 35 mg/kg

*Note: The RDA for methionine and cysteine is combined.

What About Other Ingredients?

Often, protein powders can have other ingredients in addition to the protein. Again, check the label on your specific products, as they can vary.

  • Caffeine: For more information on caffeine, check out our fact sheet: https://mothertobaby.org/fact-sheets/caffeine-pregnancy/
  • Collagen: There aren’t any studies that look at the use of collagen as a supplement during human pregnancy or breastfeeding.
  • Creatine: Creatine is naturally found in the body and in breastmilk. There aren’t any studies that look at the use of creatine as a supplement during human pregnancy or breastfeeding.

So What Now?

Emily realized that since there is not a lot of information on protein supplementation during pregnancy and breastfeeding. The best next step for her was to chat with her healthcare team about what would best support her health and pregnancy. Some providers on her healthcare team include her primary care provider, her nurse-midwife, her nutritionist, and her endocrine specialist. Emily decided that she’s even going to talk to a lactation consultant now so she can have time to prepare for breastfeeding. She knew how to measure how much protein she was getting in her protein powder, but she needed help estimating how much protein she naturally gets in her diet as well.

Have more questions about supplements or other exposures during pregnancy or breastfeeding? Talk to a teratogen-information specialist at MotherToBaby.org.

References

Elango R. & O Ball, R. 2016. Protein and amino acid requirements during pregnancy. Advances in Nutrition, 7(4): 839-844. https://doi.org/10.3945/an.115.011817.

Food and Nutrition Board. 2005. Dietary reference intakes for energy, carbohydrate, fiber, fat, fatty acids, cholesterol, protein, and amino acids. Washington, DC: The National Academies Press.

National Research Council. 1989. Recommended dietary allowances: 10th Edition. Washington, DC: The National Academies Press. https://doi.org/10.17226/1349.

U.S. Food & Drug Administration. 2025. Infant formula. https://www.fda.gov/food/resources-you-food/infant-formula


What’s the Scoop on Protein Supplements during Pregnancy and Breastfeeding?

If you are an athlete and/or have a physically active lifestyle, you may have wondered: ‘Should my exercise routine change during pregnancy and breastfeeding?’ As a former division 1 athlete and now teratogen information specialist, I sure have. You may have seen news reports about professional athletes who trained and competed at the highest level at least for some time during or shortly after their pregnancies. Serena Williams won the Australian Open while 8 weeks pregnant; Alysia Montano ran the 800 meter race at a national meet in her third trimester and Allyson Felix won a gold medal at the World Championship in track only 10 months postpartum, breaking the world record for number of gold medals won at world championships. At the same time, you may hear concerns that vigorous/strenuous physical activity can be harmful to a pregnancy. So, what is really recommended for pregnant women who have a very physically active lifestyle?

Intense Exercise and Pregnancy

Benefits of Exercise

In general, exercise is an essential element of a healthy lifestyle and is encouraged during pregnancy as a component of optimal health. Women who frequently engaged in high-intensity aerobic activity or who were physically active before pregnancy can continue these activities during and after pregnancy. Studies show many benefits: it reduces the risk of excessive weight gain, preterm birth, low birth weight, risk of C-section and developing diabetes and high blood pressure during pregnancy. Additionally, physical activity can also help with the aches and pains of pregnancy and reduce the risk of postpartum depression. Concerns that physical activity may cause miscarriage, preterm delivery or growth problems have not been proven for women with uncomplicated pregnancies.

While exercise during pregnancy is associated with minimal risks, some changes to your routine may be necessary because of normal body changes during pregnancy. Consult with your healthcare provider to determine if/how you need to adjust your exercise routine. This is even more important for women who have pre-existing health conditions.

Level and Duration of Activity

It’s important to listen to your body during pregnancy. Every pregnancy and every pregnant woman is different. The body goes through many changes during pregnancy: blood volume increases, your heart pumps harder, heart rate increases and aerobic capacity (fitness level) decreases. Additionally, many women experience nausea and fatigue throughout their pregnancy making it difficult to maintain prior exercise levels, not to mention proper nutrition and hydration. Listen to your body and don’t push it past its limits.

It’s difficult to compare vigorous/strenuous exercise between individuals. Jogging 10 miles may seem like a piece of cake for a marathon runner but could be extremely difficult for an Olympic lifter. For this reason, ‘vigorous’ activity is most frequently defined as up to 85% of capacity. While maximum effort is difficult to measure, capacity is often described in terms of maternal heart rate.

Another way to check your intensity level is the “talk test.” If you’re breathing hard but can still have a conversation easily—but you can’t sing—that’s moderate intensity. An activity would be considered vigorous if you can only say a few words before pausing for a breath.

If you were in the habit of doing vigorous-intensity exercise or were physically active before your pregnancy, vigorous exercise appears to be ok for most healthy women. However, there is limited information on individuals who exceed the accepted 85% capacity and an upper level of ‘safe’ exercise intensity hasn’t been established.

In general, it is recommended to exercise 30-60 minutes 3-4 times a week to up to daily.

What to Consider When Exercising

  • Stick with what your body is used to. If you are used to long-distance running, pregnancy is not the time to turn into a power lifter and vice versa.
  • Stay hydrated. Drink plenty of fluids before, during and after exercising.
  • Avoid overheating. Even if you are used to exercising in 90-degree heat with 70% humidity, you may have to look for an alternative method such as air-conditioned gyms. Don’t use steam rooms, hot tubs, and saunas.
  • Avoid exercises that call for you to lie flat on your back in the second and third trimester of your pregnancy because this allows less blood flow to your womb.
  • Don’t engage in sports where you could fall or get injured, or sports where you might get hit by a fast ball.
  • Reduce weight load. There is limited data on the effects of resistance training (e.g. weightlifting) on pregnancy. There is a concern that holding your breath during heavy lifts can possibly result in baby’s heart rate slowing down. Because of this, you may have to reduce the resistance load.
  • Allow enough time for your body to recover after each training session.
  • Make sure you have enough caloric intake. If you regularly participate in vigorous-intensity exercise, you will likely have to adjust your caloric intake to allow for appropriate weight gain for your pregnancy.
  • Continue to fuel your body. Prolonged high-intensity exercise can result in low blood sugar. Make sure you fuel your body if you plan on exercising over 45 minutes.
  • Check with your healthcare provider before continuing any supplements such as pre-workout protein shakes. Also, see our MotherToBaby blog on this topic.
  • Stop exercising if you feel dizzy, have a headache, develop chest pain, have calf pain or swelling, have muscle cramps, or you experience vaginal bleeding, leakage of fluid, contractions or shortness of breath before exertion. Call your healthcare provider with any concerns.

Postpartum and Breastfeeding

In general, exercise can be resumed gradually after delivery as soon as it is medically safe – consult with your healthcare provider on when they may be. This may depend on mode of delivery (c-section vs. vaginal birth) and any additional health problems or complications. When exercise can be resumed varies among women, with some being able to start exercising within days after delivery.

Regular exercise has not been shown to affect breast milk production or quality and hasn’t been shown to affect baby’s growth either. It is extremely important to remain hydrated during breastfeeding, especially when regularly exercising. All women who are breastfeeding should also focus on the correct amount of caloric intake which may vary depending on level of activity.

Bottom line is, we are all different athletes and will all have different needs during pregnancy and the postpartum period. There is no ‘one-size-fits-all’ recipe for vigorous exercising during pregnancy. The best things you can do are to consult with your healthcare provider frequently and listen to your body. For more information, see our MotherToBaby Fact Sheet on exercising. You can also find some information on which foods/drinks to limit/avoid, the appropriate amount of weight to gain, and the recommended amount of exercise here.