The Supplement Tier List: What's Actually Worth Taking
The claim: the supplement industry exists to help you optimise your health. My claim: it exists to sell you things, the overlap with what actually works is smaller than the marketing implies, and you deserve a clear, evidence-ranked breakdown of what belongs in your stack versus what belongs back on the shelf.
The supplement industry is worth roughly $170 billion globally and is almost entirely unregulated for efficacy in most markets — meaning products can be sold with health claims that have no meaningful evidence behind them, as long as the claims are phrased carefully enough to avoid regulatory action. That's the water you're swimming in every time you walk past a supplement shelf or click through a wellness ad. Most of it is profit margin and marketing dressed as optimisation.
This does not mean all supplements are useless. Some are genuinely, robustly evidence-backed and produce real, measurable benefits — and interestingly, those tend to be the cheapest and least glamorously marketed ones in the entire category. Today I want to give you the clearest, most honest ranking I can of what the evidence actually says, with particular attention to what matters for women specifically, building on the creatine conversation from Day 5 and the iron discussion from Day 8.
My thesis: a short list of supplements has strong, consistent evidence behind it and is genuinely worth considering for most training women; a longer list has weak, inconsistent, or no meaningful evidence; and the supplements most aggressively marketed to women sit predominantly in the second category rather than the first.
Evidence Tier One: Strong Evidence, Worth Considering
Creatine monohydrate — covered in depth on Day 5, but worth restating in context: the most researched performance supplement in existence, with an extensive, consistent evidence base for strength, power, muscle building, and increasingly for cognitive function and post-menopausal muscle preservation. Cheap, safe, effective. The case for it is as clean as sports nutrition gets.
Vitamin D — genuinely deficient in a large proportion of the population, particularly in northern latitudes and people with limited sun exposure, with documented effects on muscle function, bone health (directly relevant to the Day 21 and Day 46 conversations), immune function, and mood. Getting blood levels checked is the correct first step — supplementing without knowing your baseline is guessing, but if you're deficient, supplementation has real, documented benefit.
Omega-3 fatty acids — covered in Day 36 in the anti-inflammatory context. EPA and DHA from fish oil or algae-based sources have consistent evidence for reducing systemic inflammation, supporting cardiovascular health, potentially improving muscle protein synthesis, and reducing exercise-induced soreness at higher doses. The algae-based form is worth knowing about for women who don't eat fish regularly.
Iron — covered in Day 8. Not relevant for everyone, but for women with confirmed deficiency — disproportionately common in active women due to menstrual losses and training-related iron loss — targeted supplementation under medical guidance is genuinely impactful on energy, recovery, and performance. Key word: confirmed deficiency, not assumed.
Magnesium — under-consumed in most Western diets, involved in over 300 enzymatic reactions including muscle contraction, sleep regulation, and cortisol management. Magnesium glycinate or malate forms have the best absorption profiles and the fewest digestive side effects. There's consistent evidence for improving sleep quality and reducing muscle cramps, both relevant to training recovery.
The supplements with the strongest evidence tend to be the cheapest and least glamorously marketed. That inversion tells you almost everything you need to know about the industry.
Evidence Tier Two: Modest or Conditional Evidence
Caffeine — genuinely effective for acute performance — power output, endurance capacity, perceived effort reduction — with a strong, consistent evidence base. The conditional part: timing matters (morning use, not afternoon given the sleep impact covered on Day 22), tolerance builds quickly blunting the effect, and cycling off periodically restores sensitivity. Worth using strategically rather than habitually.
Collagen peptides — a genuinely interesting emerging area for connective tissue support. The evidence for direct joint and tendon benefit is growing but not yet as robust as the marketing implies, and the amino acid profile is poor for muscle protein synthesis specifically — it shouldn't replace or crowd out protein intake from complete protein sources. Worth considering for joint support alongside, not instead of, adequate total protein.
Vitamin B12 — relevant specifically for women following plant-based or predominantly vegetarian diets, where dietary B12 is consistently low. For omnivores eating varied diets, supplementation is unlikely to add benefit beyond what food provides. For vegans and vegetarians, it's non-negotiable rather than optional.
Evidence Tier Three: Weak Evidence, Save Your Money
Fat burners, thermogenics, and metabolism boosters as a category: no supplement has meaningful, consistent evidence for significant fat loss beyond what dietary and training changes produce. The small stimulant effects some contain are either replicated by caffeine alone or produce adverse effects at effective doses. The marketing-to-evidence ratio in this category is among the worst in the entire industry.
Most proprietary "women's blends," "hormone balance" formulas, and "glow complexes": typically under-dosed versions of ingredients with modest evidence at full doses, combined into formulas where the individual dose of each ingredient is too low to produce the documented effect. The complexity of the formulation is a marketing feature, not a scientific one. BCAAs for women already hitting protein targets: redundant. If your protein intake is adequate, additional branched-chain amino acids add nothing that the protein isn't already providing.
My Verdict — And Your Homework
If you currently take more than five supplements, there's a high probability at least two belong in Tier Three. The short list with strong evidence — creatine, vitamin D if deficient, omega-3s, iron if confirmed low, magnesium — costs very little and produces real outcomes. Everything beyond that deserves individual scrutiny before it costs you money it isn't earning.
Audit Your Current Stack
Write down everything you currently take. Look each one up against the tiers above — not the brand's website, which will say whatever sells it, but against published research or a reputable sports nutrition database. Anything sitting in Tier Three that you can't justify on solid evidence grounds is a candidate for removal. Put that budget toward food quality or Tier One basics instead.
