10 Ingredients to Look For (and Avoid) in Fitness Supplements

Labels matter in a make-or-break trust way with your online customers.

Fitness and wellness shoppers won’t just casually toss supplements into their carts.

They pause first. They compare. They scroll ingredient panels (and zoom in) like detectives. And the moment something feels off about what they see, they bounce.

If you sell supplements online, your ingredients are part of your conversion strategy, whether you treat them that way or not.

Let’s break down the ingredients online shoppers want to see, the ones that quietly kill confidence, and how transparency plays directly into sales, retention, and repeat purchases. See how many of your ingredients make the “must-promote” list so you know how to appeal to more buyers.

Ingredients Fitness Shoppers Actively Look For (The Good Stuff)

1. Protein (Whey, Casein, and Plant-Based Sources)

Protein is foundational, but not all protein feels equal to shoppers. Food Business News shared that today’s shoppers look for “protein, clean ingredients, and functional benefits.” That means they want to see these priorities on their protein-based products:

• Whey for fast absorption
• Casein for sustained release
• Plant-based blends for dairy-free lifestyles

Clear sourcing and protein type help shoppers self-select quickly. “Protein blend” feels vague. “Whey protein isolate” feels intentional and trustworthy.

2. BCAAs (Leucine, Isoleucine, Valine)

Branched-chain amino acids have become a familiar shorthand for muscle recovery. Shoppers who have workout routines will often associate BCAAs with:

• Reduced soreness
• Better recovery
• Less fatigue during training blocks

When listed clearly and not buried in proprietary blends, they signal performance support without gimmicks.

3. Electrolytes (Sodium, Potassium, Magnesium)

Even hydration has gone beyond the water basics. Electrolytes matter, especially for active customers who train hard, sweat heavily, or follow low-carb diets. Sodium, potassium, and magnesium reassure shoppers that your product supports real-world performance, not just aesthetics.

4. Creatine Monohydrate

Creatine is one of the most researched ingredients in fitness. Shoppers know this. Seeing creatine monohydrate listed plainly builds credibility. Hiding it or disguising it inside a blend does the opposite. Transparency here communicates buying confidence.

5. Beta-Alanine

Fitness-savvy buyers recognize beta-alanine as an endurance booster that helps buffer muscle acid buildup. They’re not expecting miracles. They’re expecting honesty. Clear labeling and dosage explanations go a long way in keeping expectations realistic and trust intact.

6. Caffeine (From Natural Sources)

Energy sells, but shoppers are cautious. Caffeine sourced from green tea, coffee bean, or guarana feels more intentional than vague “energy blends.” The key is dosage clarity. Too little feels pointless. Too much feels risky.

7. Carbohydrates (Used Intentionally)

Carbs like maltodextrin or dextrose aren’t inherently bad. Post-workout, they can help replenish glycogen stores. The problem is context. Shoppers want to know why carbs are included and how much. When brands explain usage clearly, carbs stop being a red flag and start feeling functional.

8. Antioxidants (Berries and Greens Extracts)

Antioxidants signal recovery and overall wellness. Ingredients like berry extracts or greens blends help combat exercise-induced oxidative stress and appeal to shoppers who want balance, not just bulk.

9. Nitric Oxide Boosters (Beetroot, Citrulline)

The “pump” crowd knows these ingredients well. Beetroot and citrulline are associated with blood flow and performance. When listed clearly, they help shoppers understand what kind of workout experience your product supports.

10. Healthy Fats (MCTs)

MCTs appeal to shoppers looking for quick energy, especially those following keto or low-carb lifestyles. When included intentionally and explained simply, they add versatility without confusion.

Ingredients That Raise Red Flags for Shoppers

11. Artificial Colors (Red 40, Yellow 5, Yellow 6)

Artificial dyes instantly raise skepticism. Even shoppers who aren’t deeply ingredient-focused pause when they see them. That pause often leads to comparison shopping or cart abandonment.

12. Artificial Sweeteners (Aspartame, Sucralose, Saccharin)

These sweeteners divide opinions, but gut health concerns are top of mind for wellness shoppers. When sweeteners appear without explanation, trust erodes. When alternatives are used and clearly labeled, confidence improves.

13. Fillers and Anti-Caking Agents

Ingredients like silicon dioxide, talc, or excessive magnesium stearate often feel unnecessary to shoppers. They scan the “other ingredients” section closely. Long lists here quietly undermine everything above them.

14. Proprietary Blends

Proprietary blends are one of the fastest trust killers in modern supplement shopping. Shoppers want to know dosages. When they can’t find them, they assume the worst.

15. Titanium Dioxide

Used purely for coloring, titanium dioxide has gained negative attention in recent years. Many shoppers actively avoid it, even if they can’t articulate why. Its presence creates friction that’s hard to overcome.

16. Hydrogenated Oils

Trans fats and hydrogenated oils feel outdated and unhealthy to wellness-focused buyers. Seeing them in a supplement creates an instant disconnect.

17. Excessive Maltodextrin

In small, functional amounts, maltodextrin can serve a purpose. In excess, it feels like filler. Shoppers associate it with blood sugar spikes and empty calories when overused.

18. Hidden or Dangerous Stimulants

Ingredients like DMAA or synephrine raise serious concerns, especially in pre-workouts. Even borderline stimulants cause hesitation. Transparency and restraint matter here.

19. Banned Substances

Shoppers increasingly look for certifications like NSF Certified for Sport.

Absence of third-party testing doesn’t just reduce trust. It actively deters serious athletes.

20. Excessive Stimulants Overall

More is not better. Excessive stimulant loads lead to fears of jitters, anxiety, and heart palpitations. Many shoppers have learned this the hard way and won’t risk it again.

Why Ingredient Transparency Drives Retention, Not Just First-Time Sales

When customers understand what they’re taking and why it works, they stick around. Ingredient education builds confidence after checkout. Confidence leads to repeat orders. Repeat orders build sustainable growth. This is where email and SMS shine. Post-purchase education, ingredient breakdowns, and replenishment reminders help reinforce trust long after the first sale.

Want to turn ingredient trust into higher conversions and repeat revenue? Start a free trial with Privy and see how pop-ups, email, and SMS help wellness brands educate, convert, and retain customers without feeling pushy.