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Protein Powder During Pregnancy and Breastfeeding: What Is Known and What to Check

What NHS, Health Canada and Cochrane say about protein in pregnancy and breastfeeding, and what to check on a powder label: vitamin A, caffeine, herbs, sweeteners and metals.

Content last updated . This page has not been medically reviewed.

Quick answer
The official pages we read put food first. The NHS (UK) says you do not need a special diet in pregnancy, advises protein-rich foods every day (beans, pulses, fish, eggs, lean meat, poultry, nuts), and says there is no need to "eat for 2". [1] While breastfeeding, the NHS also says no special diet is needed. [2] Neither NHS page lists protein powder as needed. Proper evidence not found for trials of everyday protein powder in pregnancy or breastfeeding: we searched PubMed for protein supplements in pregnancy and lactation and read the NHS, NCCIH and Cochrane pages below. Ask a midwife, doctor or pharmacist before starting any supplement; if you have a milk allergy and see signs of anaphylaxis, MedlinePlus says to call 911 in the US. [3]

Official protein levels

These are published reference values for groups, not advice for you. Health Canada's Dietary Reference Intakes page (dated 2025-11-19) lists:
GroupRDA, g per kg per dayRDA, g per dayNotes
Women 19 to 50 years0.8046[4]
Pregnancy, ages 19 to 501.171The page says the RDA for pregnancy applies only to the second half of pregnancy [4]
Lactation, ages 19 to 501.371[4]

The page also lists a share-of-calories range of 10 to 35% that includes pregnant and lactating women, and says grams per day come from the per-kilogram value multiplied by a reference weight. [4] Do not mix grams per kilogram with grams per day. The NHS pages we read give no gram figure for protein. The EFSA (EU) figures could not be verified because we could not read the document.

What to check on a powder label

  • Added vitamins. The NHS says not to take supplements containing vitamin A (retinol) in pregnancy because too much can harm the baby's development, and to always check the label. [7] See Prenatal and postnatal vitamins.
  • Caffeine. The NHS says not to have more than 200 mg a day in pregnancy, and notes it is found in some health or fitness supplements. [8] The same limit is given while breastfeeding. [2]
  • Herbal ingredients. The NHS says not all "natural" remedies are safe in pregnancy, some products may contain substances such as lead, and you should tell your midwife, doctor or pharmacist. [9]
  • Sweeteners. The NHS says approved sweeteners are considered safe and acceptable. [10] A 2014 review in Canadian Family Physician found available data do not suggest adverse effects in pregnancy, advised moderation within acceptable daily intakes, and noted limited data on some sweeteners. [11] See Protein powder ingredients.
  • Heavy metals. A 2020 risk assessment modeled adults, not pregnancy, and concluded typical protein powder intake did not pose an increased health risk, with the highest estimates in "mass gain" powders and the lowest in whey powders. [12] It used concentrations reported in earlier analyses rather than new testing, and it did not assess pregnancy. [12] See Heavy metals in protein powders.
  • Allergens and lactose. See Milk protein in powders.

Frequently asked questions

Is protein powder safe during pregnancy?

Proper evidence not found for a general safety statement on everyday protein powder. Check each ingredient (vitamin A, caffeine, herbs) and ask your midwife, doctor or pharmacist. [7][8][9]

How much protein is recommended in pregnancy?

Health Canada's table lists an RDA of 1.1 g per kg per day, or 71 g a day, for ages 19 to 50, applying to the second half of pregnancy. [4] The NHS advises protein-rich foods daily. [1]

Is it safe to use protein powder while breastfeeding?

Proper evidence not found. The NHS says no special diet is needed and lists protein foods, and the NCCIH notes many supplements have not been tested in nursing mothers. [2][13]

Can too much protein harm the baby?

In one trial in the Cochrane review, high-protein supplementation was linked to more small-for-gestational-age babies, and the review said it may be harmful. [5] It did not study powders in general.

Are sweeteners in protein powder a problem in pregnancy?

The NHS says approved sweeteners are safe and acceptable, and a 2014 review found no adverse effects in pregnancy but limited data. [10][11]

More details: evidence, limits and cautions

The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.

How to read the evidence labels

Labels used on this page: established (official intake values), mixed, evidence of possible harm (one trial), proper evidence not found.

What trials of protein supplements in pregnancy found
A Cochrane review (2015) pooled 17 trials in 9,030 women. [5] It found balanced energy and protein supplementation seems to improve fetal growth and may reduce stillbirth and small-for-gestational-age babies, while high-protein supplementation does not seem beneficial and may be harmful to the fetus. [5] The harm signal came from one trial: high-protein supplementation was linked to more small-for-gestational-age babies (RR 1.58). [5] The authors cautioned that quality was low for several outcomes and called for trials in women whose intake is below recommended levels. [5] A 2025 meta-analysis found balanced protein-energy supplementation helped birthweight and small-for-gestational-age outcomes, particularly in women who are undernourished. [6]

These trials tested specific supplement formulas, mostly for undernourished groups. They cannot be applied to a general protein powder or to a well-nourished person.

Safety and who should ask a clinician
  • Supplements can interact with medicines, and many have not been tested in pregnant women or nursing mothers. [13] See Medication interactions and Pregnancy and breastfeeding safety.
  • Kidney disease: the NIDDK says protein amounts should be worked out with a dietitian or health care professional. [14]
  • Gestational diabetes, liver disease, a vegetarian or vegan diet or a history of eating disorders are reasons to ask a clinician or dietitian. This is our caution; the sources above do not cover each condition.
  • For wider guidance see Preconception, pregnancy, postpartum and breastfeeding.
References
  1. NHS (UK). Have a healthy diet in pregnancy. Page last reviewed 21 April 2023. Read 2026-10-23.
  2. NHS (UK). Breastfeeding and diet. Page last reviewed 15 May 2026. Read 2026-10-23.
  3. MedlinePlus (US National Library of Medicine). Food allergy. Read 2026-10-23.
  4. Health Canada. Dietary reference intakes tables: Reference values for macronutrients. Page details date 2025-11-19. Read 2026-10-23 through a web-fetch tool, because direct download from this network failed.
  5. Ota E, Hori H, Mori R, Tobe-Gai R, Farrar D. Antenatal dietary education and supplementation to increase energy and protein intake. Cochrane Database Syst Rev 2015;(6):CD000032. Read 2026-10-23.
  6. Iftikhar A, et al. Effect of balanced protein-energy supplementation given to pregnant women on birth outcomes: a systematic review and meta-analysis. Womens Health (Lond) 2025;21:17455057251335366. Read 2026-10-23.
  7. NHS (UK). Pregnancy vitamins and supplements. Page last reviewed 3 June 2026. Read 2026-10-23.
  8. NHS (UK). Foods to avoid in pregnancy. Page last reviewed 15 June 2026. Read 2026-10-23.
  9. NHS (UK). Medicines in pregnancy. Page last reviewed 5 September 2022. Read 2026-10-23.
  10. NHS (UK). The truth about sweeteners. Page last reviewed 20 February 2023. Read 2026-10-23.
  11. Pope E. Sugar substitutes during pregnancy. Can Fam Physician 2014;60(11):1003-1005. Read 2026-10-23.
  12. Bandara SB, Towle KM, Monnot AD. A human health risk assessment of heavy metal ingestion among consumers of protein powder supplements. Toxicol Rep 2020;7:1255-1262. Read 2026-10-23.
  13. NCCIH (US National Institutes of Health). Using dietary supplements wisely. Last updated January 2019. Read 2026-10-23.
  14. NIDDK (US). Eating and nutrition for chronic kidney disease. Last reviewed January 2025. Read 2026-10-23.
Education, not medical advice. This page is for general information. It does not diagnose or treat any condition and is not a substitute for care from a qualified health professional. Natural does not automatically mean safe. Ask a clinician or pharmacist before changing your care, especially if you take medication, are pregnant or breastfeeding, or have a health condition.