Best Supplements for Muscle Growth: What Actually Works
The supplement aisle promises bigger muscles in a tub. Most of it is marketing. A handful of supplements have solid research behind them, and the rest you can skip. Here's which is which, with the doses that actually work.
Get the basics right first
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Supplements ranked by evidence
| Supplement | Evidence for muscle | What it does | Typical dose |
|---|---|---|---|
| Creatine monohydrate | Strong | More reps and strength, more muscle over time | 3–5 g a day (5–10 g for bigger guys) |
| Protein powder | Strong (as food) | Easy way to hit your protein target | 20–40 g when you need it |
| Caffeine | Strong (for training) | More energy, strength and endurance in the gym | 3–6 mg per kg, about 60 min before training |
| Beta-alanine | Moderate | Helps hard efforts lasting about 1–4 minutes | 4–6 g a day, split, for at least 2–4 weeks |
| Vitamin D | Only if you're low | General health; no proven muscle boost if your levels are normal | Get tested first |
| Omega-3 (fish oil) | Mixed | General health; effect on muscle small or unclear | Or eat oily fish 1–2 times a week |
| BCAAs | Not needed | Nothing extra if you hit your protein | Skip |
| Glutamine | Not needed | No proven muscle benefit for healthy lifters | Skip |
| Testosterone boosters | Poor | Most ingredients unproven | Skip |
| Fat burners | Poor | Mostly expensive caffeine, some with risky extras | Skip |
1. Creatine: the best supplement you can take
Creatine is the most researched supplement in sports nutrition. It helps your muscles make energy for short, hard efforts, so you can squeeze out an extra rep or two each set. Over weeks and months, that extra work adds up to more strength and more muscle.
- Dose: 3–5 g of creatine monohydrate a day, every day, is the standard dose. It fills your muscles in about 3–4 weeks.
- Higher doses: bigger, heavier guys training hard may do better on 5–10 g a day, roughly 0.1 g per kg of bodyweight (10 g at 100 kg). A review of studies in older adults found lower-body strength only improved with a loading phase followed by more than 5 g a day. For muscle mass in most guys, though, studies haven't consistently found an extra benefit above 5 g. Higher doses can upset your stomach, so split them into 2 servings.
- Loading (optional): about 20 g a day split into 4 doses for 5–7 days fills your muscles faster, then drop to 3–5 g a day.
- Timing: any time of day. Taking it daily matters far more than when.
- Which type: plain creatine monohydrate. Fancier, pricier versions haven't been shown to work better.
- Safety: the International Society of Sports Nutrition reports that doses up to 30 g a day for up to 5 years have been safe and well tolerated in healthy people. Expect around 1–2 kg of extra water weight in your muscles at first. If you have kidney problems, talk to your doctor first.
Want the full details on loading, timing, types and myths? Read our complete creatine guide.
2. Protein powder: convenient, not magic
Protein powder is just food in a convenient form. It isn't better than chicken, eggs or Greek yoghurt, but it makes hitting your daily target much easier, especially when you're busy or struggling to eat enough.
- When it helps: after training, as a snack, or when you're short on protein at the end of the day.
- Which type: whey is cheap and mixes well. Plant blends (pea and rice) work too if you avoid dairy.
- How much: a scoop usually gives 20–25 g of protein, but brands vary, so check the label.
Not sure how much protein you need? See how much protein to build muscle and the high-protein foods list.
3. Caffeine: train harder
Caffeine is one of the few supplements proven to boost performance. It can help you lift a bit more, do more reps and feel less tired during a session.
- Dose: about 3–6 mg per kg of bodyweight, roughly 60 minutes before training. For an 80 kg guy that's 240–480 mg. Start at the low end; more isn't better.
- Sources: coffee, caffeine tablets or a pre-workout (check how much caffeine it actually contains).
- Watch out: too much can cause jitters, a racing heart and poor sleep, and sleep matters more for growth than any supplement. Avoid it within 6–8 hours of bed. Most healthy adults are advised to stay under about 400 mg a day.
4. Beta-alanine: useful for high-rep work
Beta-alanine helps buffer the acid that builds up during hard efforts lasting about 1–4 minutes, like high-rep sets or circuits. It's a smaller effect than creatine, so it's optional.
- Dose: 4–6 g a day, split into smaller doses, for at least 2–4 weeks.
- Side effect: a harmless tingling in your skin. Smaller, split doses reduce it.
What you can probably skip
- BCAAs: they're already in every protein you eat. If you hit your daily protein, extra BCAAs add nothing.
- Glutamine: popular in gyms, but there's no good evidence it builds muscle in healthy lifters.
- Testosterone boosters: a study of 50 "T-booster" products found 90% claimed to boost testosterone, but only about a quarter of their ingredients had any evidence of doing so. Some contained more zinc than the safe upper limit.
- Fat burners: mostly caffeine with a big markup, and some have contained banned or risky stimulants.
- Vitamin D and omega-3: worth it for health if you're low or don't eat oily fish, but don't expect extra muscle if your levels are already normal. Ask your doctor about a blood test.
Testosterone boosters vs testosterone therapy (TRT)
These get mixed up all the time, but they're completely different things.
| Testosterone boosters | Testosterone therapy (TRT) | |
|---|---|---|
| What it is | Over-the-counter herbs, vitamins and minerals | Actual testosterone, usually injections or gels, prescribed by a doctor |
| Who it's for | Marketed to everyone | Men diagnosed with low testosterone (hypogonadism) |
| Does it raise testosterone? | Mostly no | Yes, back into the normal range |
| Effect on muscle | None proven | Modest gains in lean mass and loss of fat in men who were genuinely low |
| Monitoring | None | Regular blood tests with your doctor |
TRT has become very popular, especially with older gym-goers, because testosterone levels drop gradually with age. For men who really are low, it can improve energy, sex drive and body composition. But it's a medical treatment with real trade-offs:
- You need a proper diagnosis: symptoms of low testosterone plus low morning blood tests on two separate days. A single test or a questionnaire isn't enough.
- It shuts down your own production and usually lowers sperm count, so it can affect fertility. Tell your doctor if you may want kids.
- It can thicken your blood (raise your red blood cell count), so your doctor will check your blood and prostate (PSA) regularly.
- Heart safety: a large trial (TRAVERSE, 2023) of 5,246 men aged 45–80 with low testosterone and heart risk found TRT didn't increase major heart events compared with placebo, but there were more cases of atrial fibrillation, blood clots in the lungs and acute kidney injury.
- It's usually long term. Stopping means your levels drop again while your own production recovers.
Get tested and treated by your own doctor or an endocrinologist, and be wary of clinics that prescribe without proper testing. Before you go down this road, check the free basics that support healthy testosterone: 7–9 hours of sleep, not carrying too much body fat, regular training and eating enough.
What about steroids and SARMs?
Using anabolic steroids or SARMs to build muscle is different from TRT. Instead of bringing low testosterone back to normal under a doctor's care, it pushes hormone levels far above normal, usually without any medical monitoring. These aren't supplements: they're drugs, and in most countries they're prescription-only or banned for sale. They come with real health risks:
- Anabolic steroids can shut down your body's own testosterone production, reduce fertility, raise your risk of heart problems, cause acne and breast tissue growth, and affect mood. Some of these effects can last long after you stop.
- SARMs are sold online as "research chemicals" but aren't approved for human use. When researchers tested 44 products sold as SARMs, only about half actually contained SARMs, and many contained other unapproved drugs or nothing active at all.
- Hidden in supplements: some products sold as ordinary supplements have been found to contain undeclared steroid-like ingredients. That's a big reason to buy only third-party tested products.
Everything on Fit Gorillas is about building muscle naturally: hard training, enough food and protein, and patience. If you're thinking about using any of these, talk to a doctor first.
How to buy supplements safely
- Choose third-party tested products, such as those certified by Informed Sport or NSF Certified for Sport. They're tested for banned substances.
- Keep it simple: single ingredients (like plain creatine monohydrate) are easier to check than "proprietary blends".
- Be wary of big promises. "Pack on 10 kg in a month" is a red flag.
- Check with your doctor if you have a medical condition or take medication.
Supplements are the last 5%
Think of muscle building as a pyramid. The base is consistent hard training, then enough calories (see how many calories to build muscle), then enough protein, then sleep and recovery. Supplements sit at the very top. Get the base right and creatine plus a protein shake might give you a small extra edge. Skip the base and no tub will save you.
Frequently asked questions
What is the best supplement for building muscle?
Creatine monohydrate. It is the most researched sports supplement and helps you do more reps and build more strength and muscle over time. Take 3 to 5 g a day, every day.
Do I need protein powder to build muscle?
No. Protein powder is just a convenient food. If you hit your daily protein target from meals, you do not need it, but it makes hitting your number much easier.
Are BCAAs worth it?
Not if you eat enough protein. BCAAs are already in every protein food you eat, so taking extra adds nothing when you hit your daily protein target.
Do testosterone boosters work?
Mostly no. A study of 50 testosterone booster products found only about a quarter of their ingredients had any evidence of raising testosterone, and some contained more zinc than the safe upper limit.
Is more than 5 g of creatine a day better?
For most guys, 3 to 5 g a day is enough. Bigger guys training hard may benefit from 5 to 10 g a day, about 0.1 g per kg of bodyweight, and one review in older adults found extra strength gains with more than 5 g a day after a loading phase. Split bigger doses to avoid stomach upset.
Is TRT the same as taking steroids?
No. Testosterone therapy (TRT) is prescribed by a doctor for men diagnosed with low testosterone, and aims to bring levels back into the normal range with regular blood tests. Steroid use for bodybuilding pushes levels far above normal, usually without medical monitoring.
Is pre-workout worth it?
The main ingredient that works in most pre-workouts is caffeine. A coffee or a caffeine tablet about 60 minutes before training does the same job for less money. Check how much caffeine a pre-workout contains before you take it.
Are steroids and SARMs supplements?
No. They are drugs, prescription-only or banned for sale in most countries, with real health risks including shutting down your own testosterone, fertility problems and heart risks. Products sold as SARMs are often mislabeled.
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This article is general information for healthy adults and isn't medical advice. Talk to your doctor before taking supplements if you have a medical condition, take medication, or are under 18. Sources: Kreider et al. (2017), "International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation", Journal of the International Society of Sports Nutrition. Guest et al. (2021), "International Society of Sports Nutrition position stand: caffeine and exercise performance", JISSN. Trexler et al. (2015), "International Society of Sports Nutrition position stand: beta-alanine", JISSN. Clemesha et al. (2020), "'Testosterone boosting' supplements composition and claims are not supported by the academic literature", World Journal of Men's Health. Lincoff et al. (2023), "Cardiovascular safety of testosterone-replacement therapy" (TRAVERSE), New England Journal of Medicine. Forbes et al. (2021), "Meta-analysis examining the importance of creatine ingestion strategies on lean tissue mass and strength in older adults", Nutrients. Van Wagoner et al. (2017), "Chemical composition and labeling of substances marketed as selective androgen receptor modulators and sold via the internet", JAMA. Protein range: Morton et al. (2018), British Journal of Sports Medicine. Related reading: How much protein to build muscle · High-protein foods list · How many calories to build muscle · Body recomposition · Creatine: how much and when · Sleep and muscle growth