Protein Powder Ingredients: Sweeteners, Gums, Flavors, Added Amino Acids and Proprietary Blends
What sweeteners, gums, colors, added amino acids and proprietary blends in a protein powder mean, what FDA, NHS, WHO and EFSA say, and how to read the ingredient list.
Content last updated . This page has not been medically reviewed.
Why the ingredient list matters
Protein is only part of what is in the tub. Sweeteners, thickeners, colors and blends can affect digestion, allergies, and certain medical conditions. This page explains what the sources we read say. It names no products and gives no ranking.Sugar alcohols (polyols) such as sorbitol, xylitol, erythritol and maltitol are a separate group. The NHS says they can have a laxative effect in large amounts. [2] MedlinePlus says sorbitol, mannitol and xylitol may cause stomach cramps and diarrhea in large amounts, and notes a study linking erythritol to a mildly higher cardiovascular risk that needs more research. [4] Proper evidence not found for digestive effects of high-intensity sweeteners such as sucralose or stevia extracts in the sources we read (FDA, NHS, WHO, MedlinePlus). For pregnancy see Protein powder during pregnancy.
Gums and thickeners
Gums are food additives, and xanthan gum is one example. EFSA re-evaluated xanthan gum, authorized as a food additive in the EU, and found no need for a numerical ADI and no safety concern at the reported uses. [5] In a study cited by EFSA, 15 g a day increased stool output, bowel frequency and gas. [5] Adults tolerated large amounts, but some had abdominal discomfort that the panel considered undesirable but not adverse. [5] That is one gum; we did not read evidence on other gums used in powders.Flavors and colors
The FDA says some people have hypersensitivity reactions to color additives; one example is a yellow dye that may cause itching and hives in some people. [6] US law requires major allergen sources to be named, for example "lecithin (soy)" or "whey (milk)". [6] Proper evidence not found on "natural flavors" in protein powders: the pages we read do not discuss them. See Protein powder and food allergy.Added amino acids and how protein is counted
Protein on a US label may be calculated as 6.25 times the nitrogen content. [7] When a Percent Daily Value for protein is shown, the grams are multiplied by a protein-quality score. [7] Because protein can be calculated from nitrogen, a nitrogen-containing ingredient that is not a complete protein could in principle change the number; that is our reading of the rule, not a finding. Proper evidence not found from a regulator or journal on how common this "amino spiking" is: we searched PubMed with several phrasings and read FDA pages. See Amino spiking and label accuracy and Reading a protein powder label.Proprietary blends
For products labeled as dietary supplements, FDA guidance says a "Proprietary Blend" must list the total weight of its other dietary ingredients on the same line. [8] The ingredients inside are then listed in descending order of predominance by weight. [8] So the label shows the blend's total weight and the order, not each ingredient's amount. Ingredients that have official reference values must be listed separately. [8] The FDA guide page we read is dated 2005. [8]Frequently asked questions
Are artificial sweeteners in protein powder safe?
The FDA and NHS say approved sweeteners are safe under conditions of use, while the WHO recommends against them for weight control. [1][2][3] People with PKU should avoid aspartame. [1]
Which ingredient most often causes stomach upset?
Among sources we read, sugar alcohols have the clearest warnings: cramps and diarrhea in large amounts. [2][4]
What is a proprietary blend?
A named mix of ingredients whose total weight is listed but not each amount. [8]
Does protein powder with gums cause bloating?
One EFSA-reviewed gum, xanthan gum, increased gas in a study of 15 g a day. [5] Proper evidence not found for typical powder amounts.
Is "natural" sweetener safer?
Proper evidence not found comparing "natural" with "artificial" sweeteners. The FDA page says certain stevia and monk fruit extracts went through GRAS notices, and that whole-leaf and crude stevia extracts are not permitted as sweeteners. [1]
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 (regulator statements), mixed, proper evidence not found.
Sweeteners
| Source | What it says |
|---|---|
| FDA (US, page current 2017) | Six high-intensity sweeteners are approved as food additives: saccharin, aspartame, acesulfame potassium, sucralose, neotame and advantame. GRAS notices were submitted for certain stevia and monk fruit extracts. [1] |
| FDA | An acceptable daily intake (ADI) is the amount considered safe to consume each day over a lifetime. [1] |
| NHS (UK, 2023) | Approved sweeteners are considered a safe and acceptable alternative to sugar, and research on sweeteners and health is mixed. [2] |
| WHO (2023) | Recommends against using non-sugar sweeteners to control body weight or reduce the risk of noncommunicable diseases; the recommendation is conditional. [3] |
| WHO | The recommendation does not apply to people with pre-existing diabetes, nor to low-calorie sugars and sugar alcohols. [3] |
Phenylketonuria (PKU) is a rare inherited condition. The FDA says people with PKU should avoid or restrict aspartame because it contains phenylalanine. [1] The NHS says UK labels carry a phenylalanine warning. [2]
Safety and who should ask a clinician
- Product quality. FDA says supplement makers are responsible for evaluating safety and labeling before marketing, and FDA can act after a product reaches the market. [9] The NCCIH warns that some bodybuilding products may contain prescription drugs not allowed in supplements. [10] See Quality testing and certifications.
- Kidney disease. Phosphorus is added to many foods, and phosphorus additives are the primary source of phosphorus for many people. [11] People with kidney disease should ask their dietitian or clinician about protein products.
- Medicines, pregnancy, children, surgery. The NCCIH says supplements can interact with medicines, may not have been tested in pregnancy or children, and can pose risks before surgery. [10] See Medication interactions.
References
- U.S. Food and Drug Administration. High-Intensity Sweeteners. Content current as of 19 December 2017. Read 2026-10-23.
- NHS (UK). The truth about sweeteners. Page last reviewed 20 February 2023. Read 2026-10-23.
- World Health Organization. WHO advises not to use non-sugar sweeteners for weight control in newly released guideline. News release, 15 May 2023. Read 2026-10-23.
- MedlinePlus (US National Library of Medicine). Sugar and sweeteners. Review date 1 April 2025. Read 2026-10-23.
- EFSA Panel on Food Additives and Nutrient Sources added to Food. Re-evaluation of xanthan gum (E 415) as a food additive. EFSA Journal 2017;15(7):e04909. Read 2026-10-23.
- U.S. Food and Drug Administration. Food Allergies. Content current as of 11 March 2026. Read 2026-10-23.
- U.S. Electronic Code of Federal Regulations. 21 CFR 101.9, Nutrition labeling of food. Text as published in the version dated 2025-10-01. Read 2026-10-23.
- U.S. Food and Drug Administration. Dietary Supplement Labeling Guide: Chapter IV. Nutrition Labeling. Content current as of 1 April 2005. Read 2026-10-23.
- U.S. Food and Drug Administration. Dietary Supplements. Content current as of 1 October 2024. Read 2026-10-23.
- NCCIH (US National Institutes of Health). Using dietary supplements wisely. Last updated January 2019. Read 2026-10-23.
- NIDDK (US). Eating and nutrition for chronic kidney disease. Last reviewed January 2025. Read 2026-10-23.