Supplements
Walk into any supplement shop and you will see the front shelves dominated by testosterone boosters, fat burners, "men's vitality" stacks — products with bold claims, proprietary blends, and prices that have less to do with what is inside than with how aggressively the brand markets itself.
The supplements with the strongest evidence for actually moving the needle on testosterone, energy, and recovery are not on those front shelves. They are mundane. They are cheap. They sit in the section labelled "vitamins and minerals," and they are boring enough that no one writes Instagram posts about them. They also happen to be the ones most men are actually deficient in.
This article is the foundation tier of the supplement protocol from The Testosterone Blueprint. Five supplements. Each with a clear deficiency it addresses, evidence behind it, and a reasonable dose. No proprietary blends. No "ancient herbs from the mountains of nowhere." Just the things that work for the boring reason that they fix what is actually missing.
If you only ever take five supplements for the rest of your life, take these. The rest is decoration.
Supplements work when they fill a gap. They do not work as steroids in a capsule. Taking 10,000 IU of vitamin D when you are already at 100 nmol/L will not make your testosterone go up. Taking 10,000 IU when you are at 35 nmol/L will. The intervention is correcting a deficiency, not creating a surplus.
This matters because it changes how you think about results. You will not feel anything from any of these five in the first week. You will feel something — usually subtle, sometimes substantial — in week four through eight as your tissue levels normalise. The men who report life-changing effects from a supplement were almost always profoundly deficient in it before they started. The men who report nothing usually were not deficient to begin with.
The ideal sequence is: get a blood test (see how to read your blood test results), identify your actual gaps, then supplement accordingly. The five below are the ones that are statistically most likely to be your gaps, especially if you live in the UK or Northern Europe, eat a typical Western diet, and spend most of your time indoors.
Dose: 2,000–5,000 IU daily, with food
Target blood level: 75–150 nmol/L (30–60 ng/mL)
Vitamin D is not really a vitamin. It is a steroid hormone, synthesised from cholesterol when ultraviolet B radiation hits your skin. It is also one of the most consistently low markers in adult men, especially in the UK, where the sun strong enough to make vitamin D is available roughly five months a year, and most men spend most of those months indoors.
The hormone connection is direct. Vitamin D receptors are present in Leydig cells — the cells in your testicles that make testosterone. Men with vitamin D below 50 nmol/L have measurably lower testosterone, and correction in deficient men raises T modestly but reliably. Not dramatically — supplementing vitamin D when you are already replete does nothing for testosterone — but if you are deficient, correcting it is one of the cleanest interventions available.
Why K2 matters. Vitamin D increases calcium absorption from the gut. Without adequate vitamin K2, that calcium can end up in places you do not want it — arterial walls, soft tissue. K2 directs calcium where it should go: into bones and teeth, away from arteries. The two are designed to work together. The supplement market caught up to this years ago, and combined D3+K2 products are now standard.
What to look for: D3 (cholecalciferol, not D2), combined with K2 as MK-7 (menaquinone-7) at 100–200 mcg. A good vitamin D3 with K2 supplement in softgel form with some oil is well-absorbed and inexpensive — typically £8–15 for a 6-month supply.
Caveats: Test before going above 5,000 IU daily long-term. Vitamin D toxicity is real, though rare, and requires sustained intake above 10,000 IU for many months to develop. If you have kidney problems or take medications that affect calcium, check with a doctor before supplementing.
Dose: 300–400 mg elemental magnesium, before bed
Target: dietary intake of 400+ mg/day combined with supplementation
Magnesium is a cofactor for over 300 enzymatic reactions, including several involved in testosterone synthesis and androgen receptor function. It also regulates sleep, muscle relaxation, blood pressure, and insulin sensitivity. Estimates suggest roughly half of men in developed countries consume less than the recommended daily intake — and "recommended" is itself probably set too low.
The sleep angle matters most for testosterone. Magnesium helps regulate GABA, the calming neurotransmitter, and supports the transition into deep sleep. Deep sleep is when most daily testosterone production happens. A man who sleeps badly will have low T no matter what else he does. Magnesium will not fix bad sleep on its own, but in a sleep-deprived man with low magnesium, correction often produces noticeably better sleep within a week or two.
Why glycinate, not citrate or oxide. The form of magnesium matters more than the dose. Magnesium oxide is cheap, poorly absorbed, and useful mainly as a laxative — not what you want. Magnesium citrate is better absorbed but still has gut effects. Magnesium glycinate (or bisglycinate) is well-absorbed, gentle on the gut, and the form most relevant for sleep and testosterone support because glycine itself has calming properties.
What to look for:Magnesium glycinate at 300–400 mg elemental magnesium per dose. Check the elemental content — many products list the total weight including the glycinate, which is misleading. A 1000 mg "magnesium glycinate" capsule may contain only 100 mg of elemental magnesium.
When to take it: 30–60 minutes before bed. The sleep effect is the most consistent benefit, and you do not want it earlier in the day where the mild calming effect could blunt energy.
Dose: 25 mg daily with food, away from coffee and dairy
Target: enough to maintain blood zinc in the upper half of reference range
Zinc is directly involved in testosterone synthesis. It is also one of the most commonly deficient minerals in men, particularly those who avoid red meat, drink coffee in volume (zinc absorption is blunted by tannins), or do high-volume training (zinc is lost in sweat).
The evidence for zinc and testosterone is mixed in well-fed men and clear in deficient men. Studies in zinc-deficient men show that correction raises testosterone — sometimes dramatically. Studies in zinc-replete men show no benefit from additional zinc, and at high doses, excess zinc actually suppresses immune function and depletes copper.
The lesson: 25 mg is the sweet spot. Above 45 mg daily for sustained periods causes problems. The "more is better" approach to zinc is one of the more reliable ways to make your hormones worse rather than better.
What to look for:Zinc bisglycinate or zinc picolinate at 25 mg. Avoid zinc oxide (poorly absorbed) and zinc sulfate (rough on the stomach). Take with food, but not with coffee, tea, or dairy — these reduce absorption substantially. Evening with dinner works well.
Caveats: If you take zinc consistently above 30 mg for more than a few months, consider periodically supplementing 2 mg of copper, or taking a brief break from zinc — to avoid the copper depletion that long-term high-dose zinc causes.
Dose: 1–3 g combined EPA + DHA daily
Target: a Western diet typically delivers 0.1–0.2 g; the gap is real
Omega-3 fatty acids — specifically EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) — are anti-inflammatory, support cardiovascular health, reduce triglycerides, and improve cellular membrane function. They also matter for testosterone production indirectly, by reducing systemic inflammation, which suppresses Leydig cell function when chronic.
The typical Western diet, heavy in seed oils and light in fatty fish, produces an omega-6 to omega-3 ratio of roughly 15:1. The evolutionary ratio is closer to 1:1 to 4:1. That imbalance drives low-grade inflammation that affects everything from joint health to mood to hormonal output.
If you eat oily fish (salmon, mackerel, sardines, herring) three or more times per week, you may not need to supplement. Most men do not. For those who do not, a daily omega-3 supplement closes the gap reliably.
What to look for: A high-strength omega-3 fish oil with at least 1 g combined EPA + DHA per dose. Read the label carefully — many cheap omega-3 supplements list the total fish oil content (e.g., 1000 mg) while the actual EPA + DHA content is only 300 mg combined. Look for ones that disclose the EPA and DHA amounts clearly.
Quality matters here more than for most supplements because fish oil can become rancid. Look for products with verified low oxidation values (TOTOX, peroxide value), preferably independently tested by services like Labdoor. Triglyceride-form fish oil is better absorbed than ethyl ester form, though both work.
Caveats: Omega-3 has a mild blood-thinning effect at high doses. If you take blood thinners or have a clotting condition, discuss with your doctor. Otherwise, the safety margin is wide.
Dose: 6–10 mg daily
Target: a less famous mineral with surprisingly clean evidence
Boron is the least well-known of the five, and the one with the most asymmetric reward. The studies are smaller and fewer than for the other four — but what exists is consistent. Daily boron supplementation at 10 mg has been shown to modestly increase free testosterone, modestly decrease oestradiol, and reduce inflammation markers in trials lasting one to two weeks. The effect is small but real, and the mechanism — boron appears to slightly alter SHBG binding affinity and influence vitamin D metabolism — fits with the observed pattern.
Boron is also harmless at supplementation doses. It is found in fruits, vegetables, and nuts in the diet, and most men get 1–2 mg daily from food. Supplementing 6–10 mg pushes the dose into the range used in studies.
This one would not make the list if it cost £40 a bottle. It does not. A six-month supply is typically under £10.
What to look for:Boron glycinate or boron citrate at 6–10 mg per capsule. Take with food.
Caveats: Doses above 20 mg daily have been used in clinical settings for osteoporosis but should not be used routinely without supervision. The dose range above is well within safety margins.
You do not need to start all five at once. The more common mistake is starting eight supplements at once, feeling nothing different after a week, and quitting the lot.
A reasonable order, if you are starting from zero:
Week 1: Vitamin D3 with K2 + magnesium glycinate (before bed). Foundation. Affects sleep first, which affects everything else.
Week 3: Add zinc bisglycinate with dinner.
Week 5: Add omega-3 with breakfast.
Week 7: Add boron.
By week eight you are on the full foundation stack. Hold it for at least eight weeks before adding anything else, including any of the "hormonal support" supplements (ashwagandha, tongkat ali, fenugreek) — those go in the next tier and only after foundations are established. We have a separate guide on how to layer supplements properly.
Total cost on the foundation stack: roughly £25–45 per month depending on brand quality. That is less than two coffees per week. It is also where you get 70–80% of the supplement benefit available to a man with no specific deficiencies identified.
A few things are conspicuously absent from this list. Worth saying why.
No testosterone boosters. Proprietary "T-booster" blends marketed at men typically contain low doses of multiple ingredients with weak evidence, padded out with cheap fillers. The evidence-based testosterone-supportive supplements (tongkat ali, fenugreek, boron in some studies) work best as standalone, standardised extracts at studied doses — not bundled into a "men's vitality complex."
No tribulus. Heavily marketed, weakly supported. Studies in humans have failed to show a meaningful testosterone effect at typical doses. It is on most front-shelf men's supplement lists. It deserves to be on none of them.
No multivitamins. A daily multivitamin is not harmful, but it usually delivers low doses of many things, none of which are at clinically meaningful levels. Targeted supplementation of the deficiencies you actually have beats a shotgun approach.
No protein powder (in this list). Protein powder is a food, not a supplement. If your dietary protein is low, fixing it matters — through food first, powder second. But it is not part of the foundation supplement protocol.
No ashwagandha (yet). Ashwagandha has reasonable evidence and we recommend it for many men, but as part of the next tier — after foundations are addressed. Read our guide on supplements that are wasting your money for what to actively avoid, and our layering strategy article for what comes next after the foundation stack.
Chapter 10 of The Testosterone Blueprint covers all three tiers — Foundation, Hormonal Support, and Performance — with detailed dosing, timing, brand selection criteria, and what to cycle. Plus Card B2: the printable supplement protocol you can keep on the fridge.
Get the book →