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Four are worth it. Most of the rest is marketing.
Four supplements earn a spot in a man’s cabinet: creatine, vitamin D (only if your level is truly low), magnesium, and omega-3. Everything else in the aisle is mostly marketing printed on a Supplement Facts panel. That includes “boosters,” fat burners, “test support,” and proprietary blends.
A quick key for this page. Tier 1 means settled. Tier 2 means the signal is real but the data is incomplete. Tier 3 means the evidence is thin.
Creatine has the strongest evidence
Take creatine monohydrate, 5 g a day. It has a deeper evidence base than any other performance supplement, and we know how it works. Your muscles store it as phosphocreatine and use it to remake ATP, their fuel, during short, hard efforts. More phosphocreatine means a rep or two more before you run out. Over months, that adds up to real gains in strength and lean muscle mass, as long as you actually train.
You may gain a little weight in the first week, but that’s water pulled into your muscles rather than fat. Creatine can also raise serum creatinine, a marker doctors use to check kidneys. So tell your clinician you take it before any blood work, and let them read the result in context. If you have kidney disease, ask before you start.
People get two things wrong. First, monohydrate is the only form worth buying. The “buffered,” “HCl,” and liquid kinds cost more to fix problems monohydrate doesn’t have. Second, you don’t need a loading phase, since 5 g a day fills your muscles to the same level in about three weeks.
The open question is whether it helps your brain. Small trials hint at a benefit when people are short on sleep, but whether that holds in well-rested men is unproven (tier 2).
Vitamin D: fix a low number, don’t chase a high one
Vitamin D is worth taking if a blood test shows you’re low, which is common in men who work indoors. If you’re not low, it’s close to pointless. Your body uses vitamin D much like a hormone, and fixing a real deficiency helps your bones and muscles.
Here’s what it doesn’t do, and this part is settled. In large prevention trials, giving vitamin D to men who weren’t deficient did not lower heart events or cancer risk.
Not everyone needs a test. Your clinician can tell you if one makes sense, based on your symptoms and risk factors, like how much sun you get. The test is called 25-hydroxyvitamin D. If it shows you’re low, your clinician will tell you how much to take and when to recheck. Adding vitamin K2 is low-risk and reasonable, but the evidence for it is thin (tier 3), so don’t pay extra for the combo.
Magnesium and omega-3 help a little, but they’re oversold
Magnesium glycinate, 300–400 mg in the evening, is a fair choice. Your body needs magnesium to run hundreds of enzyme reactions, and the glycinate form absorbs better than the magnesium oxide in cheap tablets. Its effects on sleep and blood pressure are modest and clearest in men who are actually deficient (tier 2), so don’t expect a big change.
Omega-3 (EPA plus DHA) is where the marketing gets ahead of the data. The strong heart evidence is narrow: it comes from high-dose, purified prescription EPA in people with high triglycerides. That doesn’t mean a 2 g drugstore softgel does the same for a healthy man (tier 2). It’s still a reasonable pick, especially if you rarely eat fish. Buy based on the EPA plus DHA amounts on the label, and ignore the big “fish oil” number on the front. Don’t expect it to make up for a bad diet.
What to skip, and why
- Testosterone boosters. Almost all of them are junk. If your energy, sex drive, or morning erections have dropped, get a real testosterone blood test instead of an herb blend. Low T is confirmed only by symptoms plus two separate early-morning tests. If that’s you, testosterone treatment may be an option, rather than a supplement that only pretends to help. TRT can lower sperm count, so say so if you want children.
- BCAAs. If you eat enough protein, you already get them, so taking them alone adds nothing.
- Fat burners. They’re mostly caffeine with a fancy label. To be blunt, no supplement in this article changes body weight the way a prescription GLP-1 can. If losing fat is the real goal, start there.
- Proprietary pre-workouts. If the label says “blend,” you can’t know your dose. Plain caffeine plus creatine does the same job for less money.
When something else earns a spot
Berberine does lower blood sugar, but it is not “nature’s Ozempic” (tier 2). Ashwagandha has small trials for stress and sleep (tier 2–3). A plain fiber supplement helps if you can’t get enough fiber from food. Any of these can interact with prescription drugs, so check with your clinician before you add them.
The takeaway
- Buy: creatine at 5 g a day, vitamin D only to correct a low level a lab test found, magnesium glycinate, and omega-3 chosen by its EPA plus DHA amounts.
- Skip: boosters, fat burners, BCAAs, and proprietary blends.
- Creatine is settled, and the rest are tier 2. We label them so you know which is which.
