Before You Spend a Penny
The Right Way to Think About Supplements
The supplement industry is worth over $150 billion globally — and the vast majority of what it sells is either unnecessary, ineffective, or a heavily marked-up version of something cheap. Marketing budgets in this space are enormous. The gap between what's proven and what's promoted is wider than in almost any other area of health.
This guide is built around one principle: supplements supplement a good foundation — they never replace it. Sleep, training, nutrition, and stress management drive 95% of your results. Supplements, at best, add a meaningful percentage on top of that. At worst, they waste money and create the illusion of doing something productive when the real levers aren't being pulled.
The supplements in Tier 1 are the exceptions — genuinely well-supported, meaningful in their effects, and worth taking regardless of how dialled-in the rest of your routine is. Everything after that is conditional on the foundation being solid first.
Tier 1
Strong, consistent evidence across multiple studies. Worth taking for most people.
Tier 2
Good evidence with specific conditions. Useful for the right person at the right time.
Tier 3
Emerging or moderate evidence. Reasonable to consider — not essential.
The Hierarchy That Never Changes
Sleep → Training → Protein → Calories → Everything else → Supplements. If anything above supplements isn't in order, adding more pills won't fix it. Address the hierarchy first.
Non-Negotiable Foundation
Tier 1 — Take These Every Day
These supplements have the strongest evidence base, the most consistent real-world outcomes, and meaningful effects even when diet is already solid. If you're only going to take anything, take these.
Creatine Monohydrate
The single most researched supplement in existence
What It Does
Increases phosphocreatine stores in muscle — the fuel system used for explosive, high-intensity effort. Directly improves strength output, power, and training volume. Supports muscle protein synthesis and cell hydration. Emerging evidence shows cognitive benefits, particularly in sleep-deprived states and for older adults.
When
Any time — consistency matters far more than timing. Pre or post-training is fine. With food or without. It accumulates in muscle over time — missing one day is irrelevant.
Form
Creatine monohydrate only. Ignore Kre-Alkalyn, creatine HCl, buffered creatine — no evidence they outperform monohydrate at any price point. Buy the cheapest unflavoured monohydrate powder available.
Notes
No loading phase required. Initial scale weight increase (1–2kg) is water drawn into muscle — not fat. Non-responders exist (~25% of people) but most see clear benefit within 4 weeks. Safe for long-term daily use — decades of research confirm this.
Vitamin D3 + K2
The pair that most people are deficient in
What It Does
D3 regulates calcium absorption, immune function, testosterone production, mood, insulin sensitivity, and muscle function — acting more like a hormone than a vitamin. K2 directs calcium into bones and teeth rather than arteries. They must be taken together for safe, effective calcium metabolism.
Dose
2,000–4,000 IU D3 · 100–200mcg K2 (MK-7)
When
With your largest meal of the day — fat-soluble vitamins require dietary fat for absorption. Morning or evening both work.
Form
D3 (cholecalciferol) — not D2. K2 as MK-7 (menaquinone-7) — longer half-life than MK-4. Many combined D3/K2 capsules are available.
Notes
Estimated 40–60% of adults in lower-sunlight climates are deficient. Deficiency impacts testosterone, mood, immune function, and training recovery simultaneously. Blood test (25-OH Vitamin D) confirms status — optimal range is 40–60 ng/mL.
Magnesium Glycinate
The most underrated supplement for active people
What It Does
Cofactor in over 300 enzymatic reactions. Supports ATP production, muscle contraction and relaxation, protein synthesis, sleep quality, blood pressure regulation, and stress response. Lost significantly through sweat — active individuals are commonly deficient even with a good diet.
Dose
200–400mg elemental magnesium
When
30–60 minutes before bed. The parasympathetic activation from magnesium directly supports sleep onset and quality. One of the most reliable sleep quality interventions available without a prescription.
Form
Glycinate for sleep and recovery (well-absorbed, gentle on digestion). Malate for energy and muscle function taken earlier in the day. Citrate if constipation is a factor. Avoid oxide — poor absorption.
Notes
Check the elemental magnesium content on the label — not the total compound weight. A 500mg magnesium glycinate capsule typically contains ~50–80mg elemental magnesium. Aim for 200–400mg elemental total per day from supplements plus food.
Omega-3 Fish Oil
EPA & DHA — anti-inflammatory essential fats
What It Does
EPA and DHA are long-chain omega-3 fatty acids with extensive evidence for reducing systemic inflammation, supporting cardiovascular health, improving insulin sensitivity, reducing muscle soreness, supporting joint health, and aiding muscle protein synthesis. Brain and mood benefits are well-documented.
Dose
2–3g combined EPA + DHA daily
When
With meals — reduces the fishy aftertaste and improves absorption alongside dietary fat. Can be split across two meals if taking a larger dose.
Form
Check the label for EPA + DHA content specifically — not just "fish oil" total. Triglyceride form is better absorbed than ethyl ester. Algae-based omega-3 is an effective vegan alternative (DHA and EPA directly — not ALA).
Notes
Store in the fridge to prevent oxidation. Rancid fish oil smells strongly — if it does, throw it out. Those on blood thinners should consult their doctor before taking high doses. Aim for at least 2 fatty fish meals per week from food alongside supplementation.
Protein Supplement
Whey, casein, or plant — a tool not a replacement
What It Does
Closes the gap between dietary protein intake and your target. Does not build muscle on its own — it provides the raw material that training turns into muscle. Convenient, fast-digesting, and cost-effective per gram of protein. Whey has the highest leucine content of any protein source — the amino acid most responsible for triggering muscle protein synthesis.
Dose
25–40g per serving · as needed to hit daily target
When
Wherever it fits your day — post-training is convenient but not mandatory. Breakfast if protein is low there. As a snack. Before bed (casein — slower digesting) if struggling to hit targets and sleep-time muscle protein synthesis is a goal.
Form
Whey concentrate (budget-friendly, contains some lactose). Whey isolate (higher protein per gram, minimal lactose — better for sensitive stomachs). Casein (slower digesting, good pre-bed). Plant blend (pea + rice protein covers all essential amino acids — viable alternative for vegans).
Notes
Buy based on protein per serving and cost per gram — not flavour marketing or endorsements. Avoid products with lengthy ingredient lists, proprietary blends, or added creatine/amino acids that inflate serving weight. Simple is better.
Caffeine
The most evidence-backed performance enhancer available
What It Does
Blocks adenosine receptors — reducing perceived fatigue and effort. Increases adrenaline, improves focus, and enhances endurance, strength output, and power. One of the most studied ergogenic aids with consistent performance benefits across virtually all exercise types.
Dose
3–6mg per kg bodyweight pre-training
When
30–60 minutes before training. Critically — cut off at least 8 hours before sleep. Caffeine has a 5–6 hour half-life. A 3pm coffee at 200mg still has 100mg active at 9pm. Poor sleep from late caffeine undoes the performance benefit entirely.
Form
Coffee is a perfectly adequate source. Caffeine anhydrous (tablets or pre-workout powder) allows precise dosing. Avoid pre-workouts with proprietary blends — you don't know what you're taking or at what dose.
Notes
Tolerance builds quickly — cycling off periodically restores sensitivity. Consider 1–2 caffeine-free days per week or a periodic 1–2 week washout. Don't train without caffeine only on race days or key sessions — you need to train without it too so performance isn't dependent on it.
Worthwhile With the Right Context
Tier 2 — Situational but Well-Supported
These supplements have good evidence and meaningful effects — but whether you need them depends on your diet, health status, training goals, or specific gaps. Assess which apply to you before adding them.
Zinc
Testosterone, immunity & recovery
What It Does
Required for testosterone synthesis, immune function, protein synthesis, and wound healing. Active individuals lose zinc through sweat at a meaningful rate — making deficiency common in people who train regularly, eat little red meat, or follow plant-based diets.
Dose
15–30mg elemental zinc daily
When
With food — reduces nausea. Avoid taking at the same time as iron or calcium supplements as they compete for absorption.
Form
Zinc picolinate or bisglycinate — best absorbed forms. Avoid zinc oxide (poor bioavailability). Long-term supplementation above 40mg/day depletes copper — add 1–2mg copper if supplementing zinc daily for extended periods.
Iron
Only if confirmed deficient — critical for performance
What It Does
Oxygen transport via haemoglobin and myoglobin. Iron deficiency — even without full anaemia — directly limits endurance, strength output, cognitive function, and recovery. Disproportionately affects women who menstruate and those with high training volumes.
Dose
As directed by blood work — typically 18–45mg elemental iron
When
On an empty stomach for best absorption — or with Vitamin C if stomach upset occurs. Avoid with coffee, tea, calcium, or antacids which significantly reduce absorption.
Form
Ferrous bisglycinate (gentle, well absorbed, minimal GI side effects). Ferrous sulphate (cheaper, more common, can cause constipation).
Notes
Do not supplement iron without a confirmed blood test. Excess iron is pro-oxidant and harmful. Test ferritin (stores) and serum iron — ferritin below 30 ng/mL warrants attention even without anaemia symptoms.
Beta-Alanine
Muscular endurance — sustained high-intensity effort
What It Does
Increases muscle carnosine levels — the buffer that delays the acidification that causes the "burn" during high-rep sets or sustained effort. Most beneficial for efforts lasting 60–240 seconds. Directly improves performance in high-volume training and conditioning work.
When
Timing is not critical — carnosine accumulates over time (4–12 weeks of consistent use). Split into smaller doses (0.8–1.6g) to reduce paraesthesia (harmless tingling sensation). Often included in pre-workouts.
Notes
Less beneficial for pure strength or power work (under 60 seconds). Most valuable for conditioning, circuit training, metabolic work, and high-rep hypertrophy sets. The tingling is harmless — not an adverse reaction.
Citrulline Malate
Blood flow, pump & endurance
What It Does
Increases arginine and nitric oxide production — improving blood flow and oxygen delivery to working muscle. Reduces muscle fatigue and soreness post-training. Improves endurance capacity and rep output in resistance training. One of the more evidence-backed pre-workout ingredients.
Dose
6–8g citrulline malate (2:1 ratio)
When
30–60 minutes before training. Note: most pre-workouts underdose this — check the label. 6g is the minimum effective dose in studies.
Notes
Pure L-citrulline is also effective at half the dose (3–4g) with similar results. More practical for those mixing their own pre-workout stack. Generally well-tolerated — mild GI discomfort at very high doses.
Vitamin B12
Non-negotiable for vegans — important for over 50s
What It Does
Essential for red blood cell formation, DNA synthesis, neurological function, and energy metabolism. Deficiency develops slowly and is often missed until significant — causing fatigue, brain fog, weakness, and nerve damage. Found almost exclusively in animal products.
Dose
500–1,000mcg daily (oral) · or 1,000mcg sublingual
When
Any time — water-soluble, excess excreted. Morning is convenient. Sublingual (under the tongue) improves absorption for those with absorption issues.
Form
Methylcobalamin is better absorbed and utilised than cyanocobalamin — particularly for those with the MTHFR gene variant. Both work for most people.
Notes
Essential for all vegans and most vegetarians. Increasingly important for everyone over 50 — intrinsic factor (required for B12 absorption) declines with age. Annual blood test to monitor levels is worthwhile.
Collagen + Vitamin C
Connective tissue, joints & tendons
What It Does
Hydrolysed collagen peptides — particularly when taken with Vitamin C before training — increase collagen synthesis in connective tissue. Supports tendon and ligament health, joint comfort, and recovery from connective tissue injuries. Particularly relevant for anyone with joint discomfort or a history of tendon issues.
Dose
15g hydrolysed collagen + 50mg Vitamin C
When
30–60 minutes before training — the window when collagen synthesis in connective tissue is most active post-exercise. This timing is specific and matters for the connective tissue benefit.
Notes
Not a replacement for muscle-building protein — collagen lacks sufficient leucine to drive muscle protein synthesis. Think of it as connective tissue maintenance, not a protein source. Gelatin is an inexpensive whole-food alternative to collagen peptides with the same amino acid profile.
Ashwagandha
Stress, cortisol & recovery adaptogen
What It Does
An adaptogen — helps the body regulate its stress response. Evidence shows meaningful reductions in cortisol, improved stress and anxiety scores, better sleep quality, and modest testosterone increases in stressed or sleep-deprived individuals. Also shows strength and recovery benefits in some training studies.
Dose
300–600mg KSM-66 or Sensoril extract daily
When
Evening — the cortisol-lowering effect supports sleep quality. Can be split morning and evening if taking a higher dose.
Notes
Benefits are most pronounced in people with high baseline stress or cortisol — less impactful if stress levels are already low. KSM-66 and Sensoril are standardised root extracts with the most clinical evidence. Not recommended in pregnancy. Effects build over 4–8 weeks of consistent use.
Electrolytes
Sodium, potassium, magnesium — for training & hydration
What It Does
Replenishes sodium, potassium, and magnesium lost through sweat. Maintains fluid balance and nerve/muscle function during and after training. Prevents the decline in performance and the cramping that comes from electrolyte depletion — particularly relevant in hot conditions or high-volume training.
Dose
1 serving during or after training sessions over 60 minutes
When
During longer training sessions, in hot/humid conditions, or after heavy sweat sessions. Not necessary for every gym session — most short sessions are adequately covered by a balanced diet.
Notes
Avoid sugar-loaded sports drinks — look for electrolyte products with minimal sugar and meaningful sodium (500mg+), potassium, and magnesium content. A simple DIY option: water with a pinch of sea salt, squeeze of lemon, and a small amount of coconut water.
Emerging & Specialist
Tier 3 — Optional but Reasonable
These supplements have emerging or moderate evidence. Not essential — but reasonable to consider once Tier 1 and relevant Tier 2 are in place. Think of them as refinements, not foundations.
L-Theanine
Focus + calm — caffeine's ideal pairing
What It Does
Amino acid found naturally in green tea. Promotes alpha brain wave activity — alert relaxation without sedation. When combined with caffeine, reduces the jitteriness and anxiety caffeine can cause while preserving the focus and performance benefits. A well-tolerated and elegant pairing.
Dose
100–200mg with caffeine (2:1 theanine:caffeine ratio)
When
Alongside pre-workout caffeine. Also useful standalone in the evening for relaxation without drowsiness — supports sleep onset without impairing next-day alertness.
Rhodiola Rosea
Mental fatigue & stress resilience adaptogen
What It Does
Adaptogen with evidence for reducing mental fatigue, improving cognitive performance under stress, and supporting exercise capacity. Activates different pathways to ashwagandha — more stimulating, less sedating. Good for periods of high mental and physical load.
Dose
200–600mg standardised extract (3% rosavins, 1% salidroside)
When
Morning or pre-training — stimulating effect means evening use can disrupt sleep. Can be cycled: 5 days on, 2 days off.
Berberine
Blood sugar, insulin sensitivity & metabolic health
What It Does
Activates AMPK — a key metabolic regulator. Improves insulin sensitivity, reduces fasting blood glucose, and supports lipid metabolism. Often compared to metformin in mechanism. Relevant for body composition, particularly for those with insulin resistance or high carbohydrate diets.
Dose
500mg 2–3x daily with meals
When
With carbohydrate-containing meals for maximum effect on blood sugar. Not a supplement to take indefinitely — cycle on and off (8–12 weeks on, 4 weeks off).
Notes
Can interact with medications — consult a doctor if on any prescription drugs, particularly diabetes or cardiovascular medications. May cause GI discomfort initially.
Melatonin
Sleep timing — not a nightly dependency
What It Does
Signals the brain that it's time to sleep — it doesn't sedate like a sleeping pill, it adjusts the sleep clock. Effective for jet lag, shift work, and resetting disrupted sleep timing. Less effective for general insomnia where the sleep clock is functioning normally.
Dose
0.5–1mg — more is not better
When
30–60 minutes before target sleep time. Low doses (0.5mg) are as effective as high doses (5–10mg) — the industry oversells dose. High doses cause morning grogginess and can disrupt the natural melatonin rhythm with chronic use.
Notes
Not intended for nightly long-term use — use situationally. For chronic sleep issues, magnesium glycinate, sleep hygiene, and breathwork address root causes rather than just signalling.
NMN / NR
NAD+ precursors — cellular energy & longevity
What It Does
NAD+ (nicotinamide adenine dinucleotide) is a coenzyme central to energy production and cellular repair. NAD+ levels decline with age. NMN (nicotinamide mononucleotide) and NR (nicotinamide riboside) are precursors that raise NAD+ levels. Emerging research shows mitochondrial, cognitive, and muscle recovery benefits — particularly in those over 40.
Dose
250–500mg NMN or NR daily
When
Morning — NAD+ is involved in circadian rhythm regulation. Some evidence suggests morning dosing aligns better with natural NAD+ fluctuation patterns.
Notes
Expensive. Evidence is promising but still maturing — most strong data is in animal models or older adults. More relevant as a longevity supplement for those over 40 than as a performance supplement for younger active people. Not a priority until Tier 1 and 2 are fully in place.
Probiotics
Gut health, immunity & absorption
What It Does
Supports gut microbiome diversity — which influences immune function, nutrient absorption, inflammation, and mood via the gut-brain axis. Specific strains show evidence for reducing upper respiratory tract infections in athletes, improving GI comfort, and supporting immune resilience under high training loads.
Dose
10–50 billion CFU daily — multi-strain formula
When
With food — reduces stomach acid exposure to the bacteria. Consistency matters more than timing.
Notes
Whole food sources (yoghurt, kefir, sauerkraut, kimchi, miso) provide probiotic benefit alongside prebiotic fibre — a strong foundation before considering supplements. Refrigerated products generally have better bacterial viability than shelf-stable capsules.
Save Your Money
What to Avoid
The supplement industry makes most of its money from products that don't work, are wildly overdosed, or are cheap ingredients dressed up in expensive marketing. These are the most common offenders.
Fat Burners
Almost universally a combination of stimulants (caffeine, synephrine), diuretics, and appetite suppressants packaged as a weight loss solution. The caffeine works — and costs pennies per dose bought separately. Everything else either doesn't work or carries risk.
Testosterone Boosters
No over-the-counter supplement meaningfully raises testosterone in healthy individuals. The ingredients that show any effect (zinc, Vitamin D, ashwagandha) work by correcting deficiencies — and are far cheaper bought individually. Proprietary blends in these products are typically underdosed.
BCAA Supplements
Branched-chain amino acids — leucine, isoleucine, valine — are found in every protein source you eat. If you're hitting your protein target, you don't need them. Adding BCAAs on top of adequate protein intake has no additional muscle-building benefit. Expensive amino-flavoured water.
Proprietary Blends
Any supplement that lists a "proprietary blend" with a total weight but no individual ingredient doses is hiding underdosed ingredients behind marketing. You cannot assess whether you're getting an effective dose of anything. Avoid entirely.
Detox & Cleanse Products
Your liver and kidneys are your detox system — and they work continuously without assistance. No supplement "detoxes" your body or "flushes toxins." These products exploit a scientifically meaningless concept and are at best harmless and at worst dangerous.
Pre-Workouts with Proprietary Blends
Most pre-workouts are caffeine plus underdosed ingredients marketed as a complex formula. The caffeine works. The rest is usually below the clinically effective dose. Build your own stack: caffeine + L-theanine + citrulline + beta-alanine — cheaper, transparent, and effective.
Meal Replacement Shakes
Highly processed, expensive, and nutritionally inferior to real food. A protein shake is a supplement — a meal replacement that bypasses actual eating does nothing to build the habits and food relationship that make body composition change sustainable.
Collagen as a Protein Source
Collagen lacks sufficient leucine — the amino acid most responsible for triggering muscle protein synthesis. It has a specific, useful role in connective tissue health (with Vitamin C, pre-training), but it is not a substitute for complete protein sources. Don't count it toward your protein target.
HMB (standalone)
A metabolite of leucine marketed for muscle preservation. The evidence supporting meaningful benefit in people already hitting their protein target is weak and inconsistent. When protein intake is adequate — which it should be — HMB adds nothing. Fix protein first.
The One Question That Filters Most Bad Supplements
Before buying anything, ask: "Is this ingredient listed at the clinically effective dose from the research?" If the label shows a proprietary blend, an undisclosed dose, or a dose significantly below what studies used — it won't work. The marketing budget for a supplement is often inversely proportional to the quality of its evidence.
Put It Into Practice
Your Practical Stacks
Four ready-to-use stacks built from the tiers above — matched to common goals and situations. These are starting points, not rigid prescriptions. Build from Tier 1 outward.
For Everyone — Start Here
The Foundation Stack
Creatine monohydrate
5g daily
Vitamin D3 + K2
3,000 IU D3 · 150mcg K2
Magnesium glycinate
300mg before bed
Omega-3 fish oil
2–3g EPA+DHA with meals
Protein (if needed to hit target)
25–40g as required
Strength & Body Composition
Performance Stack
Foundation stack (all 5)
As above
Caffeine pre-training
3–5mg/kg bodyweight
L-Theanine with caffeine
200mg
Citrulline malate pre-training
6–8g
Beta-alanine (if high volume)
3.2–6.4g split doses
Zinc (if low meat intake)
15–25mg with food
Stress, Recovery & Sleep
Recovery Stack
Foundation stack (all 5)
As above
Ashwagandha KSM-66
300–600mg evening
L-Theanine (standalone)
200mg evening
Electrolytes post-training
1 serving after sessions
Collagen + Vit C pre-training
15g + 50mg
Melatonin (travel/disruption only)
0.5–1mg situationally
Plant-Based & Vegan Athletes
Vegan Stack
Creatine monohydrate
5g daily — especially important
Vitamin D3 (vegan) + K2
3,000 IU D3 · 150mcg K2
Vitamin B12 (methylcobalamin)
1,000mcg daily
Algae-based omega-3 (DHA+EPA)
2–3g daily
Iron (if confirmed deficient)
Per blood work
Zinc bisglycinate
15–25mg with food
Plant protein blend (pea + rice)
25–40g as needed
The Final Word
The gap between the person who takes every supplement perfectly and the person who trains consistently, eats enough protein, and sleeps well — is smaller than the supplement industry wants you to believe. Build the foundation. Then supplement it. In that order, always.