The Complete Supplement Guide for Beginners

The supplement industry is worth over $150 billion annually and growing. It is also one of the most aggressively marketed, least regulated, and most confusing spaces in health and fitness. For a beginner standing in a supplement store, or scrolling through Instagram ads, the noise is overwhelming.

This guide cuts through it. You'll learn which supplements have genuine evidence behind them, what dosages actually work, what's overhyped, and how to build a stack that makes sense for your goals and budget.

Pin it

The Evidence Tier Framework

Not all supplements are created equal. The research quality behind different products varies enormously. A useful framework:

Tier 1, Strong evidence (multiple high-quality RCTs)

• Creatine monohydrate
• Caffeine
• Protein supplements (when dietary protein is insufficient)
• Vitamin D (for deficient individuals)
• Omega-3 fatty acids (EPA/DHA)
• Magnesium (for deficient individuals)

Tier 2, Promising evidence (some RCTs, effect sizes variable)

• Beta-alanine
• Citrulline malate
• Ashwagandha
• Collagen peptides
• Probiotics
• Berberine

Tier 3, Limited or weak evidence (mostly in vitro, animal, or poorly designed studies)

• Most "fat burners"
• Testosterone boosters
• Proprietary blends with undisclosed doses
• Most "detox" supplements
• BCAAs (if dietary protein is adequate)

The rule: start with Tier 1, add Tier 2 selectively based on specific goals, avoid Tier 3 entirely.

The Core Stack: What Most People Need

1. Creatine Monohydrate

Creatine is the most researched supplement in sports nutrition history, over 500 peer-reviewed studies. It works, it's safe, and it's inexpensive.

What it does: Increases phosphocreatine stores in muscle, allowing your body to regenerate ATP (energy currency) faster during high-intensity efforts. This translates to more reps per set, faster recovery between sets, and, over time, meaningfully greater strength and muscle mass gains.

Who benefits: Anyone doing resistance training, HIIT, or high-intensity sports. Less relevant for pure endurance activity (long-distance running, cycling).

Dosage: 3–5g daily. No loading phase required (loading is optional and simply saturates stores faster). Take it every day, consistency matters more than timing.

Form: Creatine monohydrate. Ignore "creatine HCL," "Kre-Alkalyn," and other variants, monohydrate has the research base and is the cheapest form.

Side effects: Water retention of 1–2kg in the first 2–3 weeks (muscle draws water in with creatine, this is not fat gain). Some people experience mild GI discomfort, split into two doses if so.

2. Protein Powder

Protein powder is not a special muscle-building substance, it's food. Specifically, it's a convenient, cost-effective way to hit a high daily protein target when whole food sources are impractical.

Who needs it: Anyone struggling to hit 1.6–2.2g of protein per kg bodyweight through food alone. If you're already hitting your target with chicken, eggs, dairy, and fish, you don't need powder.

Types:

• Whey concentrate (80%): Most cost-effective. Contains some lactose, use isolate if lactose intolerant.
• Whey isolate (90%+): Higher protein per serving, minimal fat and lactose, more expensive.
• Casein: Slow-digesting, useful as a pre-bed option to sustain muscle protein synthesis overnight.
• Plant protein blends (pea + rice): Comparable to whey for muscle building when total daily protein is adequate. Essential for vegans/vegetarians.

Dosage: As needed to reach your daily protein target, typically 1–2 scoops (25–50g protein) per day.

3. Vitamin D3

Vitamin D deficiency affects an estimated 40% of adults in northern Europe and North America. It's implicated in immune function, testosterone levels, mood regulation, bone density, and recovery.

Who needs it: Anyone living above 35° latitude (UK, most of Europe, Canada), virtually everyone from October to April. Also people who work indoors, use sunscreen consistently, or have darker skin.

Dosage: 1,000–2,000 IU daily is the typical maintenance dose. If you have a confirmed deficiency (blood test), 4,000 IU under medical guidance.

Form: D3 (cholecalciferol), not D2 (ergocalciferol). D3 is the form your body produces from sunlight and is better absorbed.

Take with: A meal containing dietary fat (vitamin D is fat-soluble).

4. Omega-3 (EPA/DHA)

Omega-3 fatty acids, specifically EPA and DHA from marine sources, support heart health, reduce systemic inflammation, may improve insulin sensitivity, and support joint health.

Who needs it: Anyone not eating 2–3 portions of oily fish per week (salmon, mackerel, sardines, herring). Most people.

Dosage: 2–3g of combined EPA + DHA daily. Check the label, many cheap fish oil capsules are 1,000mg fish oil but only 300mg EPA/DHA.

Form: Fish oil (standard) or algae oil (for vegans, this is where fish get their omega-3 from).

Pin it

Performance Supplements (For Those Who Train Consistently)

Caffeine

Caffeine is one of the most effective ergogenic (performance-enhancing) supplements available. It is also freely available in coffee, tea, and energy drinks.

What it does: Blocks adenosine receptors in the brain, reducing perceived effort and fatigue. Meaningfully increases endurance performance, and modestly improves strength and power output.

Dosage: 3–6mg per kg bodyweight, 30–45 minutes before training. Start at the lower end (3mg/kg) and assess tolerance.

Tolerance: Regular caffeine use builds tolerance quickly. Cycling off caffeine for 1–2 weeks periodically restores sensitivity.

Note: If you already drink coffee, your morning coffee counts toward your caffeine intake. Pre-workouts are largely just caffeine with marketing, make your own "pre-workout" with a strong coffee and save money.

Beta-Alanine

Beta-alanine increases muscle carnosine levels, which buffers the acid build-up that causes the "burn" during high-rep sets and short-duration intense efforts.

Who benefits: Most useful for efforts lasting 60–240 seconds, high-rep strength training, CrossFit, 400–800m running. Less relevant for pure strength (low-rep) work.

Dosage: 3.2–6.4g daily. Must be taken consistently (daily) to build carnosine levels, acute doses don't work.

Side effect: Harmless tingling/flushing (paraesthesia), this is normal and subsides with regular use. Split the dose to reduce intensity.

Citrulline Malate

Citrulline converts to arginine in the body, increasing nitric oxide production and blood flow. Evidence suggests it reduces fatigue and may improve endurance-type performance.

Dosage: 6–8g citrulline malate (or 3–4g L-citrulline) 30–60 minutes before training.

Note: This is a component of many pre-workout formulas, but often under-dosed. Check labels, you need the full dose.

Supplements for Specific Goals

For Fat Loss

There are no safe fat-burning supplements that meaningfully accelerate fat loss beyond a calorie deficit. Full stop. The most commonly marketed fat burners (CLA, green tea extract, raspberry ketones) have negligible effect sizes in well-controlled studies.

Caffeine has a small thermogenic effect (~80–150 kcal/day at typical doses) and is the one genuine exception, but it's a stimulant effect, not a magic fat burner.

What actually works for fat loss: A well-structured calorie deficit, adequate protein, resistance training, and consistency. No supplement replaces this.

For Sleep and Recovery

Magnesium glycinate or bisglycinate: Many people are magnesium deficient. Magnesium supplementation can improve sleep quality, reduce cortisol, and support hundreds of enzymatic processes. 200–400mg glycinate form, 30–60 minutes before bed.

Ashwagandha (KSM-66 extract): An adaptogen with emerging evidence for cortisol reduction, sleep quality improvement, and modest testosterone support. 300–600mg KSM-66 standardised extract, taken daily. See our full ashwagandha guide.

For Hormonal Health (Women)

Inositol (myo-inositol): Particularly relevant for women with PCOS. Myo-inositol improves insulin sensitivity and may support hormonal balance. See our inositol for PCOS guide.

Collagen peptides: Primarily a joint and skin supplement. Not a substitute for dietary protein for muscle building. 10–15g daily, with vitamin C for optimal absorption. See our collagen guide.

Pin it

What to Look for on a Supplement Label

Before buying any supplement, check:

1. Active ingredient dose: Compare to the clinically studied dose. Many products under-dose to reduce cost.
2. Proprietary blends: If ingredients are listed as a "blend" with a total weight but no individual doses, you cannot verify effective dosing. Avoid.
3. Third-party certification: Informed Sport, NSF Certified, or USP verified. This confirms label accuracy and tests for banned substances.
4. Fillers and additives: Not inherently harmful, but minimally processed products are generally better.
5. Price per serving vs. price per kg: Marketing inflates per-serving price. Calculate cost per gram of active ingredient.

Supplements You Don't Need (As a Beginner)

BCAAs: If you're eating adequate protein (1.8–2.2g/kg), BCAAs are redundant, your protein already contains all essential amino acids. A complete protein source is far more cost-effective.

Testosterone boosters: Virtually no clinical evidence for effectiveness at over-the-counter doses. Most contain zinc and vitamin D, if you need those, buy them separately for a fraction of the price.

Most "fat burners": Thermogenic complexes produce negligible real-world fat loss effect. The only active ingredient with meaningful effect is caffeine, which you can get from coffee.

Glutamine: Useful only for preventing muscle catabolism in elite endurance athletes or clinical GI conditions. No benefit for recreational gym-goers eating adequate protein.

Detox products: The liver and kidneys are your detox system. No supplement meaningfully enhances their function in a healthy person.

Building Your Stack: A Beginner Protocol

Months 1–3 (Foundation):

• Creatine monohydrate: 5g/day
• Protein powder: as needed to hit protein target
• Vitamin D3: 2,000 IU/day (October–April in northern latitudes, year-round if indoors)
• Omega-3: 2–3g EPA+DHA/day

Months 4–6 (Add if training consistently):

• Magnesium glycinate: 300mg before bed
• Caffeine: coffee or supplement 30–45 min pre-workout

Months 7+ (Goal-specific additions):

• Ashwagandha: 300–600mg KSM-66 (if stress/cortisol is high)
• Collagen: 10–15g (if joint support needed)
• Beta-alanine: 3.2–6.4g/day (if doing high-intensity training)

The Bottom Line

Supplements are the finishing touch on a solid foundation of training, nutrition, sleep, and consistency. The core stack, creatine, protein (if needed), vitamin D, and omega-3, costs under £50 per month and provides the majority of supplementation benefits available.

Beyond the core stack, add goal-specific supplements selectively and based on evidence, not marketing. Third-party tested products from reputable manufacturers are worth the modest premium.

For personalised supplement timing, use our Supplement Timing Calculator to map when to take each supplement around your training schedule.

Sources

1. International Society of Sports Nutrition position stand: creatine supplementation, Kreider et al., JISSN, 2017
2. Caffeine and exercise performance, Grgic et al., Nutrients, 2019
3. Omega-3 fatty acids and exercise-induced inflammation, Smith et al., Clinical Journal of Sport Medicine, 2011
4. Vitamin D and athletic performance, Cannell et al., Scandinavian Journal of Medicine & Science in Sports, 2009