What is in your protein powder?

If you enjoy pure, unflavored whey protein, then by all means, keep doing your thing. However, companies usually add ingredients to give their product a marketing edge (such as a better flavor), so it’s worth considering if any of these additives should be sought out — or avoided.


Food preservation covers the use of physical and chemical methods to inhibit microbial growth and retain nutritional quality over time, thereby preventing or slowing decomposition. Traditional methods involved manipulating a food’s temperature (boiling, freezing) or physical state (drying, fermentation) or applying natural chemicals (sugar, salt ...). Often, these methods were combined into processes, such as curing (drying, smoking, and salting).

Today, these methods are still used, though often with a modern touch. For instance, pasteurization has replaced boiling, but both involve heating; spray-, freeze-, and vacuum-drying are modern methods of dehydration; and artificial preservatives have superseded sugar and salt. Advances in food technology have also led to novel methods of food preservation, such as irradiation.

Protein powders are preserved through drying, as dehydration (removal of the water content) inhibits microbial growth. It is therefore uncommon for protein powders to contain preservatives, be they natural or artificial. Plus, many preservatives cannot legally be used in protein powders (regulations state not only which preservatives can be used, but in which foods a specific preservative can be used; if a type of food isn’t listed, it is excluded by default). The preservatives you may encounter include notably vitamin C (ascorbic acid or ascorbate), vitamin E (tocopherol), and sorbates (calcium, potassium, or sodium sorbate).

Anticaking agents

Anticaking agents are food additives added to powders to prevent clumping (caking). They work either by absorbing moisture or by coating particles to make them water repellent.

Some common anticaking agents include magnesium stearate, silicon dioxide, calcium silicate, tricalcium phosphate, and stearic acid. You may even see powdered rice used. Most anticaking agents are natural products with well-established metabolic fates (meaning that what happens to them after ingestion is well documented). Magnesium stearate, for example, is simply a combination of magnesium (an essential mineral) and stearic acid (a saturated fatty acid). Calcium silicate is a combination of calcium (an essential mineral) and silica (a trace mineral). At food- additive doses, there is no risk of harm.

A study in some anticaking agents (tricalcium phosphate, calcium silicate, calcium stearate, corn starch, and silicon dioxide) found they hasten the degradation of vitamin C powder in high humidity (>75%),166 but vitamin C is known to degrade in the presence of water, whereas protein powders are not.

Soy lecithin

Because no one likes a clumpy protein shake, many whey protein powders contain lecithin, a natural emulsifier that helps the whey protein dissolve in liquids. Lecithin can be found in every cell in your body. The different types of lecithin are composed of various phospholipids, such as phosphatidylcholine (PC), phosphatidylethanolamine (PE), and phosphatidylinositol (PI).

It has been known for decades that dietary lecithin, within the normal diet or as a supplement, gets incorporated in cell membranes and has beneficial health effects on the cardiovascular, nervous, and immune systems. But the amounts in food and supplements are far greater than those found in whey protein powders using lecithin as emulsifier (150–300 milligrams per 30 grams of protein powder, typically: a 0.5–1% concentration).

Lecithin was first identified in egg yolks (and named after them) and has since been found in a variety of foods, with the most common sources today being soybeans and sunflower seeds. Soy lecithin is what you’re most likely to find in whey protein powders, but there is no shortage of articles demonizing it as the worst thing since trans fats simply because it is derived from soybeans.

First, consuming a little soy lecithin as an additive is very different from drinking 3 quarts (2.8 liters) of soy milk per day, as was doing a 60-year-old man when he started suffering from erectile dysfunction, decreased libido, and gynecomastia (an enlargement of breast tissue in men).

Second, most negative perceptions about soy are false, including the idea that regular consumption decreases testosterone and interferes with thyroid function.

Third, soy lecithin oil is nearly 100% fat; it contains very little residual protein and isoflavones (a.k.a. phytoestrogens), the two components that are believed to be implicated in most of soy’s purported negative effects on health. You may have heard that a study “found soy lecithin to be strongly estrogenic”, but its own data hardly support such a strong conclusion. Having found no trace of genistein (soy’s main isoflavone), the authors went to assume that soy lecithin contains “a so-far unidentified estrogen-like compound”. Not only that, but they found estrogenic activity in 3 out of 5 infant formulas — one of the formulas with soy lecithin had no estrogenic activity, and one of the formulas with estrogenic activity had no soy lecithin.

There are also many claims about soy lecithin retaining nasty chemicals supposedly used in its production. Such claims don’t provide credible sources, when they provide any sources at all. As it stands, soy lecithin production is pretty straightforward: soy oil is degummed, which simply means it is mixed with water in order to partly separate its lecithin component, then this component is dried into a powder.

Finally, some people don’t have anything against soy lecithin unless it is sourced from genetically modified (GMO) soy. Ignoring the GMO safety debate, soy lecithin is so far removed from soybeans that it contains little to no genetic material and can’t be traced back to the soybeans from which it came. So any concerns over GMOs are irrelevant to soy lecithin.

Really, the only potential concern with soy lecithin is allergy. Soy protein is a common allergen, but as we said, commercial soy lecithin contains very little residual protein: a mere 100–1,400 parts per million (according to the European Lecithin Manufacturers Association, de-oiled soya lecithin is just 0.000065–0.00048% protein). Tested against the immune cells of adults with a soy allergy, soy lecithin caused little to no reaction.