Three supplements I take and the eight I quit after research

I had eleven supplement bottles in the kitchen cupboard at one point. Two years of slowly reading actual papers later, three remain. The rest are in a bag I keep meaning to drop at a pharmacy take-back program. Here's what's still in the cupboard and what isn't.

I'm not a doctor. None of this is medical advice. If you take medication, ask the doctor before adding anything. The honest baseline is that most healthy adults eating a varied diet don't need supplements at all.

Vitamin D3 — the one with real evidence for most northern adults

If you live above about 40°N latitude (most of Europe, Canada, the northern US), you almost certainly get inadequate sun exposure from October to April to maintain healthy vitamin D levels. A blood test will tell you. Most people who get tested are insufficient. I take vitamin D3 2000 IU daily October through April, then drop to summer sun.

The 5000 IU and 10,000 IU mega-doses sold widely are not what the evidence supports for most people. 1000-2000 IU is the boring, well-supported range. Take it with a meal that contains fat — it's fat-soluble, absorption matters. Skip the gummy versions; they have less D3 per dollar and more sugar than you'd expect.

Creatine monohydrate — boring, cheap, well-studied

I take 5g of creatine monohydrate daily. About €15 for a 500g tub that lasts three months. Mix it into a glass of water or juice. No loading phase needed for general use — just take 5g/day and your muscle stores fill up over about four weeks.

The evidence base is genuinely strong: small but real strength gains, modest muscle volume, and emerging signal on cognitive performance especially for people who don't eat much red meat. Look for the "Creapure" certification on the label if you want German-made monohydrate, but unbranded micronised monohydrate is chemically identical and cheaper.

Skip creatine HCL, creatine ethyl ester, and creatine nitrate. They cost two to four times as much as monohydrate and have no proven advantage. The supplement industry invents new forms specifically to charge more. Don't fall for it.

Magnesium glycinate — the one I'm least sure about

I take 200-300 mg of magnesium glycinate at night. The evidence for magnesium supplementation is weaker than for D3 or creatine. The honest case: a lot of adults don't hit the RDA from food, magnesium is involved in muscle relaxation and sleep, and glycinate is well-absorbed without the laxative effect of magnesium oxide or citrate.

If you sleep fine and don't get muscle cramps, you probably don't need this. I noticed mild improvements in sleep quality; I might be fooling myself. The cost is low (€20 for three months) so I keep taking it. If I had to drop one of the three, this would go first.

Don't bother with magnesium oxide. It's the cheapest form by weight and the worst absorbed. The €5 bottle at the pharmacy is mostly going to your toilet, not your bloodstream.

The eight I quit

I quit a multivitamin first. Twenty-plus randomised trials show essentially no benefit on long-term health outcomes for adults with reasonable diets. The boutique €40 daily packs are the same story at four times the price. Eat a varied diet instead.

I quit fish oil. The cardiovascular evidence largely failed to replicate in the big trials of the last decade. If you eat fatty fish twice a week, you don't need it. If you don't, switch to eating fish twice a week — it's better food and better evidence than the capsule.

I quit turmeric/curcumin. Poor oral bioavailability, mixed trial results, and the bright-orange marketing dramatically outruns the data. Cook with the spice if you like the flavour. Skip the capsules.

I quit BCAA powders. If you eat any reasonable amount of protein (and you should — about 0.8 to 1g per pound of bodyweight if you lift), you get all the BCAAs you need from food and from whey protein. The €40 tub of artificially-coloured BCAA powder is the supplement industry at its purest.

I quit ZMA (zinc-magnesium-aspartate). The original 2000 trial showing testosterone increases failed to replicate. The magnesium I already take separately. Zinc you get from a normal diet.

I quit collagen peptides. The small trials showing skin and joint benefits are real but the effect sizes are tiny and the cost-per-month is high. Eat protein, do strength training, sleep enough. The collagen powder is a luxury, not a tool.

I quit probiotics. Strain-specific evidence exists for a few conditions; the over-the-counter shotgun blends do not have evidence that they meaningfully colonise the gut. Eat fermented foods (yogurt, kefir, sauerkraut) instead — same idea, better evidence, cheaper.

I quit apple cider vinegar capsules. Whatever modest blood sugar effects might exist from drinking the vinegar before a high-carb meal, the capsules don't replicate. This was the most clearly-just-marketing of the bunch.

What to do instead of buying supplements

Sleep seven to nine hours. Lift weights twice a week. Walk every day. Eat protein at every meal. Eat vegetables. Drink water. Get sunlight in the morning. These cost nothing and do more than every bottle in the supplement aisle put together.

The €60/month I used to spend on the cupboard now goes to better groceries. That's the actual upgrade.