Guide

Which supplements work and which don't

Three supplements have good evidence: creatine, caffeine and protein. The rest of the supplement shelf does nothing at best, and at worst costs you money and risks your health.

Updated October 16, 2026

How to tell what works

Reviews, before-and-after photos and "clinically proven" on the tub mean nothing. What's worth looking at is the position stands of professional societies and meta-analyses — summaries of many studies in people.

I sort supplements onto three shelves: they work, they work in specific cases, and they don't work. Spend your money and attention from the top down, not on whatever is advertised the loudest.

One more filter: an honest label. A supplement that "works like a steroid" sometimes turns out to contain one: something was mixed in. If the promised results are too loud, that's a reason to be suspicious, not to buy.

What works: creatine, caffeine, protein

Creatine monohydrate — 3–5 g a day. The ISSN position stand (Kreider et al., 2017) calls it the most effective over-the-counter supplement for lifters. More in the guide on creatine.
Caffeine — 3–6 mg per kg of bodyweight an hour before training, per the ISSN position stand (Guest et al., 2021). More in the guide on caffeine.
Protein — not a stimulant but food. The Morton et al. (2018) meta-analysis: supplemental protein helps people who aren't getting enough. More in the guide on whey protein.

What works in specific cases

Vitamin D, iron and other vitamins and minerals — they help if you're low. You find that out from a blood test and a doctor, not from how you feel.
Beta-alanine — for efforts lasting one to a few minutes. In lifting sets of 5–10 reps the effect is modest.
Electrolytes — for long sessions in the heat when you sweat a lot.

If you're not sure you need any of these, you most likely don't. Or ask a doctor.

BCAAs

BCAAs — branched-chain amino acids — are three of the twenty amino acids that make up protein. They're sold as "muscle protection" and "recovery". But any complete protein — meat, fish, eggs, dairy, protein powder — already contains them, along with the other amino acids you also need to grow.

If you eat about 1.6 g of protein per kg of bodyweight a day, BCAAs add nothing. If you don't, buy protein powder: it has the same BCAAs plus everything else, and it's usually cheaper per gram.

Testosterone boosters

Herbal "boosters" — tribulus, fenugreek and blends with loud names — promise more testosterone and muscle. There's no solid evidence that they build muscle or strength in healthy men. Where something does change, it's not a difference you'll see on the bar.

If you suspect your hormones really are off — fatigue, libido, mood — that's a question for a doctor and blood work, not a tub from the supplement store.

Fat burners

Most of them are caffeine plus plant extracts in a nice tub with a loud name. Fat comes off when you eat fewer calories than you burn — and no other way. Without a deficit a fat burner removes nothing, and with one it adds almost nothing beyond the caffeine.

The risk is real, though: strong stimulants, sometimes banned substances that aren't on the label. Spend the money on protein-rich food instead. How to cut without tubs is in the guide on cutting without losing muscle.

Safety and quality

Supplements are checked less strictly than medicines: what's inside may not match the label.
Pick products with third-party lab testing — especially if you compete and get drug tested.
A promise of "10 lb of muscle in a month" is a reason not to buy.
Health conditions, pregnancy, regular medication — talk any supplement over with a doctor first.

I'm a coach, not a doctor: this is what's known about healthy adults.

Where to start

The order in which things actually pay off:

A program with progressive overload and consistent training.
Sleep — 7–9 hours.
Calories for your goal and about 1.6 g of protein per kg of bodyweight — the protein calculator works it out.
Creatine and, if you like, caffeine before training.

Until the first three are in place, no tub will help. The easiest way to check them is your log: are your weights and reps going up from month to month?

If you're not sure what to take, take nothing: it's free and it won't hurt.

Log your workouts — the weights going up in your diary are more honest than any tub. I'll show you whether what you're doing works.

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