5 Key Takeaways From Our Protein Supplement Survey

1. Most respondents noticed improved muscle strength 

Since starting their protein supplement, 78 percent of respondents said they noticed improved muscle strength. More specifically:

• Around 12 percent experienced “significant improvement” in muscle strength
• Thirty-six percent saw a “slight improvement”
• Almost 30 percent reported “moderate improvement”

Meanwhile, 22 percent reported no noticeable change in muscle strength, and only one respondent reported a decrease. 

When asked what muscle-related benefits they were hoping to achieve from taking a protein supplement, 62 percent said “reduce age-related muscle loss” (the most common response). The second-most common reason was to “stay active and independent,” chosen by 54 percent of respondents. 

“It feels good taking something that will help slow down the loss of strength and stamina. I want to be able to maintain my active lifestyle, so my wife and I can do all the things we want during retirement,” one respondent explained. 

2. Whey was the most popular type of protein

Forty-one percent of respondents reported taking whey as their protein source. Whey powder, derived from milk, is generally regarded as the superior protein source for older adults looking to stimulate muscle growth. The second-most common type of protein, chosen by 34 percent, was collagen, followed by plant-based options such as pea, soy or rice, at around 15 percent.

3. Taste matters

Seventy-seven percent of all respondents said taste was an important factor when choosing a protein supplement. And around 81 percent reported being either “very” or “somewhat” satisfied with the taste and texture of the supplement they take. 

After taste, 65 percent of respondents selected the amount of protein per serving as an important factor. Coming in third, chosen by 49 percent of respondents, was ingredient quality, followed closely by the type or source of protein (42 percent).

4. Digestive discomfort was a common side effect 

“Feeling full” was the most commonly cited unwanted side effect of taking protein supplements (33 percent), with general “digestive discomfort” coming in a close second (30 percent). 

“Protein supplements make my stomach uncomfortable,” one respondent said. “They make me feel full, and occasionally I get constipation,” another wrote.

Some older adults may have difficulty digesting concentrated protein or experience an upset stomach from certain ingredients in the powder, such as lactose, artificial sweeteners or additives, says Morgan Pearson, a registered dietitian and AARP medical reviewer. 

Fourteen percent experienced unplanned weight gain due to their protein supplement. And twenty-two percent of survey respondents reported no unwanted side effects from taking their protein supplement.

5. Price was the biggest barrier to consistent use

Price was the most challenging part of taking supplements regularly, cited by one-third of respondents. “I’m happy that I’m doing a positive thing for my health, but I regret that they are so expensive,” one respondent wrote. 

The majority of respondents (59 percent) spend $39 or less per month on their protein supplements. Of those, 67 percent said their protein supplement is a “good” or “excellent” value. If you’re looking for more affordable ways to increase your protein intake, read our guide on 10 cheap sources of protein. 

Other challenges to using protein supplements included “forgetting to take them” (18 percent), and being “unsure about which products to take” (10 percent). Twenty-seven percent of respondents said they’ve experienced “no major challenges.”

Our AARP Smart Picks team is here to help reduce the amount of legwork you have to do when searching for the best supplements. We perform in-depth, objective evaluations of every product we recommend, so you don’t have to sift through endless options on your own. Our independent older-adult testers also provide unbiased, firsthand feedback on each of our top picks. So if you’re looking for the best protein supplements, we’ve got you covered.

Questions or feedback? Email us at AARPSmartPicks@aarp.org.