Which Supplements Are Actually Worth Taking? A Science-Based Guide

The supplement industry is worth billions, built largely on promises that outpace evidence. Most supplements are unnecessary, some are useful, and a few are actually worth your money. Here's what science actually supports.

The Honest Truth About Supplements

They're Supplements, Not Replacements

Supplements cannot:

Replace a poor diet
Make up for bad sleep
Compensate for inconsistent training
Provide magic results

They can:

Fill genuine nutritional gaps
Provide convenience
Offer modest benefits in specific contexts

Most People Don't Need Most Supplements

If you eat a varied diet with adequate protein, sleep well, and train consistently, you're already doing 95% of what matters. Supplements are the last 5%.

Tier 1: Actually Useful (Strong Evidence)

Creatine Monohydrate

What it does: Increases phosphocreatine stores for high-intensity exercise Evidence: Hundreds of studies, one of the most researched supplements Benefits:

Modest strength and power gains (5-10%)
May increase muscle mass
Cognitive benefits in some populations
Very safe long-term

Dose: 3-5 grams daily (no loading needed) Cost: Very affordable Verdict: If you strength train, this is worth taking

Vitamin D

What it does: Hormone precursor affecting bones, immunity, mood, and more Evidence: Strong, especially for deficiency correction Who needs it:

Most people in northern latitudes
Those who work indoors
Darker skin tones (reduced synthesis)
Elderly populations

Signs of deficiency:

Fatigue
Bone/joint pain
Frequent illness
Depression

Dose: 1,000-4,000 IU daily (get tested to dial in) Cost: Very affordable Verdict: Worth taking for most people, especially in winter

Protein Powder

What it does: Convenient protein source Evidence: Strong for protein's benefits (muscle building, satiety) When useful:

Difficulty meeting protein goals through food
Post-workout convenience
Travel or busy schedules

Types:

Whey: Fast-digesting, complete amino profile
Casein: Slow-digesting, good before bed
Plant-based: Pea, rice, hemp for vegans

Dose: As needed to hit protein targets Verdict: Not magic, but useful for convenience

Omega-3 Fatty Acids (Fish Oil)

What it does: Provides EPA and DHA for inflammation, heart, and brain health Evidence: Strong for those who don't eat fatty fish Benefits:

Cardiovascular health
Reduced inflammation
Brain health
Joint health for some

Who needs it: Those eating less than 2 servings of fatty fish per week Dose: 1-3 grams combined EPA/DHA daily Cost: Moderate Verdict: Worth it if you don't eat fish regularly

Tier 2: Situationally Useful (Moderate Evidence)

Caffeine

What it does: Stimulant affecting alertness and performance Evidence: Strong for performance enhancement Benefits:

Improved endurance (2-4%)
Enhanced strength performance
Increased alertness
Reduced perceived effort

Best for: Pre-workout energy, performance boost Dose: 3-6 mg/kg body weight, 30-60 minutes before exercise Note: Coffee provides similar benefits and is cheaper Verdict: Works, but you might not need a supplement—coffee counts

Magnesium

What it does: Essential mineral for hundreds of bodily functions Evidence: Moderate; many are deficient Who might benefit:

Those with poor sleep
Muscle cramps
Stress and anxiety
Athletes (lost in sweat)

Dose: 200-400 mg daily Form: Glycinate for sleep, citrate for general use Verdict: Worth considering if symptoms suggest deficiency

Beta-Alanine

What it does: Increases carnosine for buffering muscle acidity Evidence: Moderate for specific activities Benefits:

Improved performance in 1-4 minute efforts
May help with high-rep training

Note: Causes harmless tingling sensation Dose: 3-6 grams daily Verdict: Useful for specific training, not essential

Citrulline

What it does: Increases nitric oxide for blood flow Evidence: Moderate Benefits:

May improve endurance performance
Better muscle pumps
Possible recovery benefits

Dose: 6-8 grams citrulline malate pre-workout Verdict: Some benefit, not essential

Tier 3: Probably Not Worth It (Weak Evidence)

BCAAs (Branched Chain Amino Acids)

The marketing: Essential for muscle building! The reality: If you eat adequate protein, BCAAs are redundant When potentially useful:

Fasted training (maybe)
Very low protein diets

Verdict: Save your money, eat protein instead

Glutamine

The marketing: Recovery and immune support! The reality: Your body makes plenty; supplementation shows minimal benefit for healthy people Verdict: Not worth it for most people

Testosterone Boosters

The marketing: Natural testosterone enhancement! The reality: Most do nothing or have minimal effect Exception: Some herbal compounds have modest effects (ashwagandha, tongkat ali) but nothing dramatic Verdict: Skip the expensive proprietary blends

Fat Burners

The marketing: Accelerate fat loss! The reality: Mostly caffeine and questionable ingredients What actually works: Calorie deficit Verdict: Waste of money; caffeine alone does the same thing

Pre-Workout Supplements (Most)

The reality: Overpriced caffeine with pixie-dusted other ingredients Better approach: Coffee + creatine covers the effective ingredients Verdict: Often not worth the premium price

What About Multivitamins?

The debate: Insurance policy vs. expensive urine

Arguments for:

Covers potential gaps
Cheap peace of mind
Some populations benefit

Arguments against:

Most nutrients come from food
May provide nutrients you don't need
False sense of security about diet quality

Verdict: Not harmful, but not magic. If you eat a varied diet, probably unnecessary. If your diet is limited, may provide some value.

Red Flags in Supplement Marketing

"Proprietary blend": Hides actual ingredient amounts—often underdosed

Outrageous claims: "Gain 10 pounds of muscle in 2 weeks!"

Before/after photos: Often manipulated, not representative

"Clinically proven": What dose? What population? Was it the actual product or an ingredient?

Natural doesn't mean safe: Many natural substances can be harmful

How to Evaluate a Supplement

Ask These Questions

What does the research actually show? (Check examine.com)
What dose was studied? (Is the product providing that?)
Who benefits? (Are you in that population?)
What's the magnitude of effect? (Worth the cost?)
Are there side effects? (Even natural things can harm)

Where to Check

Examine.com: Evidence-based supplement analysis
PubMed: Primary research
ConsumerLab: Third-party testing
NSF Certified for Sport: For athletes concerned about banned substances

A Sensible Supplement Stack

For Most People

Definitely consider:

Vitamin D (especially in winter)
Protein powder (if needed for convenience)
Creatine (if strength training)

Maybe:

Fish oil (if not eating fatty fish)
Magnesium (if signs of deficiency)

Total cost: $30-50/month

What You Can Skip

Expensive pre-workouts (use coffee)
BCAAs (eat protein)
Most fat burners (they don't work)
Testosterone boosters (minimal effect)
Proprietary blends (unknown doses)

The Bottom Line

Most supplements are marketing, not medicine.

The few that work:

Creatine (if you lift)
Vitamin D (if deficient or limited sun)
Protein powder (for convenience)
Fish oil (if you don't eat fish)

Everything else is either:

Situationally useful at best
A waste of money at worst

Spend your money on quality food, good sleep, and consistent training first. Supplements are the cherry on top—not the sundae itself.