Supplements 101: What’s Actually Worth Taking?

Supplement shelves — and social media — promise faster results, bigger muscles and better performance from a seemingly endless list of products. Most of that promise doesn’t hold up. This guide sorts the small number of genuinely well-evidenced supplements from the much larger pile of marketing.

Key Takeaways

Most people can meet their nutritional needs through food, but a small number of supplements have strong, consistent evidence behind them.
Creatine and protein powder have the strongest evidence base for training performance and convenience respectively.
Many popular supplements — BCAAs, most "fat burners," and most branded blends — have weak or no evidence of extra benefit beyond what a good diet already provides.
UK supplements are regulated as food, not medicine, so product quality varies meaningfully between brands.
A sensible starting stack is small: get the fundamentals right before adding anything else.

Walk into any supplement shop and you’ll find hundreds of products, each promising something slightly different — faster recovery, bigger pumps, sharper focus, more muscle. Most of that marketing outpaces the actual evidence by a wide margin. A small number of supplements are genuinely well-supported; the rest range from "plausible but unproven" to "essentially food-flavoured hope."

This guide sorts supplements into three honest categories — strong evidence, mixed or emerging evidence, and not generally worth it — so you can spend your money on what actually helps.

How to Evaluate a Supplement

Before looking at specific products, it’s worth having a simple framework. Ask three questions: Is there consistent, independent research behind it? Does the claimed benefit actually matter for your goals? And could you get the same benefit from food instead? Supplements that pass all three are worth considering; most don’t.

Supplements With Strong Evidence

Creatine

Creatine monohydrate is one of the most thoroughly researched sports supplements available, with strong evidence for improved strength, power and repeated high-intensity performance. See our Creatine Guide for a full breakdown of dosing, safety and who should avoid it — it’s genuinely one of the few supplements where the evidence is close to settled.

Protein Powder

Protein powder is simply a convenient, concentrated protein source — not a requirement, but a genuinely useful tool if you struggle to hit your target through food alone. See Protein Explained for how much protein you actually need and where to get it, from food or supplements.

Vitamin D

In the UK, limited sunlight for much of the year means many people don’t get enough vitamin D from sun exposure alone. The NHS recommends everyone consider a daily supplement during autumn and winter, and some people year-round — one of the few supplement recommendations that applies broadly, not just to people who train.

Omega-3 / Fish Oil

Oily fish (or a fish oil supplement if you don’t eat much of it) provides omega-3 fatty acids linked to cardiovascular and general health benefits. The evidence here is solid for general health; the evidence for a meaningful direct effect on muscle growth or training performance specifically is much thinner.

Supplements With Mixed or Emerging Evidence

Pre-Workout / Caffeine

Caffeine, the active ingredient in most pre-workout products, has reasonably good evidence for a short-term boost in alertness and perceived effort during training. Branded pre-workout blends often add several other ingredients with far weaker individual evidence — you can usually get the core benefit from caffeine alone, at a fraction of the cost.

BCAAs

Branched-chain amino acids were popular for years on the theory that they’d support muscle repair. In practice, if you’re already eating adequate total protein — see Protein Explained — BCAAs on top of that rarely add a meaningful extra benefit, since whole protein sources already provide them.

Multivitamins

A multivitamin is a reasonable insurance policy if your diet is genuinely inconsistent, but it isn’t a substitute for eating a varied diet, and there’s little evidence it improves training performance in someone who already eats reasonably well.

Supplements Generally Not Worth It

Most "fat burner" products, branded muscle-building blends with proprietary formulas, and supplements claiming to dramatically boost testosterone or hormone levels fall into this category. The common thread: bold marketing claims, thin or absent independent research, and effects that — where studied at all — tend to be small or inconsistent.

How to Choose a Safe, Quality Supplement

In the UK, supplements are regulated as food, not medicine, meaning quality control varies meaningfully between brands. Where possible, choose products independently tested by a recognised scheme such as Informed Sport — this matters even if you’re not competing, since it’s a reasonable proxy for a manufacturer taking quality seriously, and it’s essential if you’re subject to anti-doping testing.

Building a Beginner Supplement Stack

If you’re starting from scratch, there’s no need for a long list. A sensible, well-evidenced starting point is: protein powder if your diet doesn’t easily hit your target, creatine if you’re strength training regularly, and a vitamin D supplement given typical UK sunlight levels. Everything else is optional, and most of it is unnecessary until the fundamentals — training, sleep, and overall diet — are already solid.

Common Mistakes

Expecting a supplement to fix an inconsistent diet or training routine. No supplement compensates for irregular training or a genuinely poor diet — supplements work at the margins, not as a substitute for the fundamentals.
Buying based on marketing rather than evidence. Bold claims and impressive packaging aren’t a substitute for independent research; if a product sounds too good to be true, it usually is.
Stacking too many products at once. Taking several supplements simultaneously makes it hard to tell what — if anything — is actually helping, and adds unnecessary cost.
Ignoring quality and safety testing. Especially relevant for anyone subject to drug testing, or simply wanting confidence in what’s actually in the product.

Medical Disclaimer

Speak to a doctor before starting any new supplement if you take medication, have a health condition (particularly kidney, liver or heart-related), or are pregnant or breastfeeding — some supplements can interact with medication or aren’t well-studied in these groups. Supplements aren’t appropriate for under-18s without professional guidance.

Frequently Asked Questions

Do I need supplements to build muscle?

No. Consistent training, adequate protein and sufficient calories are what actually drive muscle growth — supplements are a convenience on top of that, not a requirement.

What supplements actually work?

Creatine and protein powder have the strongest evidence for training-related benefits. Vitamin D has strong evidence for general health, particularly in the UK.

Is pre-workout safe?

For most healthy adults, moderate caffeine intake is considered safe, but check the total caffeine content and how it interacts with any other caffeine sources in your day. Those sensitive to caffeine, or with certain health conditions, should be more cautious.

Do I need a multivitamin if I exercise?

Not necessarily. If your diet is varied and reasonably consistent, a multivitamin adds little. It’s more useful as a safety net for an inconsistent diet than as a performance tool.

Are BCAAs worth it?

Generally not, if you’re already eating enough total protein. Whole protein sources already provide the same amino acids.

What supplements are a waste of money?

Most "fat burners," proprietary muscle-building blends, and testosterone-boosting products fall into this category — bold claims with thin independent evidence behind them.

How do I know if a supplement is safe?

Look for third-party testing (such as Informed Sport), check for a clear, non-proprietary ingredient list, and be cautious of anything promising dramatic or rapid results.

Can I take creatine and protein powder together?

Yes — there’s no known issue combining them, and many people take both in the same shake for convenience.

References

General Guidance on Dietary Supplement Use and Safety — NHS
Guidance on Vitamin D Supplementation — NHS
Position Stand: Protein and Exercise — International Society of Sports Nutrition
Guidance on Supplement Quality and Independent Testing — UK Anti-Doping / Informed Sport

Author's Note

The supplement industry thrives on the idea that you’re missing something essential. Almost always, you’re not — the fundamentals do the vast majority of the work, and the handful of supplements genuinely worth taking are neither expensive nor complicated.

Most supplements aren’t necessary, and the ones that genuinely help are a short list, not a long one. Get training, sleep and overall diet right first — see our Complete Beginner’s Guide to Strength Training if you’re just getting started — and treat supplements as a small, optional addition on top, not a shortcut around the basics.