If you want to lose fat while keeping or building muscle, two supplements have clearly earned their place: protein, if food alone doesn’t get you to your target, and creatine monohydrate. Caffeine can help you train harder if you tolerate it. Most of the rest has small, mixed or weak evidence.
This guide ranks the popular cutting and recomp supplements by the strength of the research, gives research-based doses, shows a simple stack and explains why yohimbine deserves serious caution.
None of these products replaces the three things that do most of the work: a moderate calorie deficit, progressive strength training and enough protein.
What actually drives a cut or recomp
A cut works because you take in a little less energy than you use. A recomp works when that deficit is modest and your training gives your muscles a reason to stay. Our guide to how a calorie deficit works explains how to size yours.
- A moderate deficit: very large deficits make it harder to train hard and hold on to muscle.
- Progressive strength training: at least two sessions a week, with loads or reps creeping up over time.
- Enough protein: spread across the day.
- Sleep: poor sleep makes training, hunger and recovery harder.
Supplements sit on top of that base. With that in mind, here’s how they compare.
Cutting and recomp supplements at a glance
| Supplement | What it may do | Evidence | Research-based amount | Main caution |
|---|---|---|---|---|
| Protein | Supports muscle and strength gains with training | Strong | About 1.6–2.2 g/kg/day total protein | Kidney disease: ask your doctor |
| Creatine monohydrate | More strength and lean mass with training | Strong | 3–5 g/day | Small rise in body weight |
| Caffeine | Better strength, power and endurance | Strong for performance | 3–6 mg/kg about 60 min before; as low as 2 mg/kg may work | Total intake, sleep, anxiety, heart |
| Beta-alanine | Helps hard efforts lasting about 1–4 minutes | Strong for that type of effort | 4–6 g/day in split doses | Tingling (paresthesia) |
| HMB | Lean mass, mainly in newer lifters | Moderate; less clear in trained lifters | 3 g/day split into 1 g doses | Low priority |
| Green tea extract | Possible modest effect on body weight | Modest | No established dose | Rare liver injury; contains caffeine |
| Ashwagandha | Stress and sleep | Limited | Varies by extract | Liver, thyroid, medications |
| L-carnitine | Claimed fat burning | Little to none | Not recommended | Cost with little payoff |
| CLA | Claimed fat loss | Weak | Not recommended | Effects too small to matter |
| Yohimbine | Claimed “stubborn fat” loss | Insufficient | Not recommended | Heart rhythm, blood pressure, anxiety, seizures |
Start here: protein and creatine
Protein
Protein is the base of any recomp. A 2018 meta-analysis of 49 trials with 1,863 participants found that adding protein during resistance training increased strength and lean mass, although the average extra gain was modest, about 0.3 kg of fat-free mass.
Gains leveled off at around 1.6 g of protein per kilogram of body weight per day, and the authors suggested about 2.2 g/kg for people who want to maximize their gains. That works out to roughly 0.7–1 g per pound. While cutting, treat 1.6 g/kg as a sensible minimum rather than a ceiling.
A powder is simply a convenient way to close the gap if food falls short. Our guide on how much protein to eat to lose weight covers food-first options.
Creatine monohydrate
Creatine is one of the most studied sports supplements. The International Society of Sports Nutrition (ISSN), in its 2018 research review, calls creatine monohydrate the most effective nutritional supplement available for increasing high-intensity exercise capacity and muscle mass during training. The same review reports no compelling evidence of harm in otherwise healthy people.
The simplest approach is 3–5 g a day, which raises muscle creatine over about three to four weeks. A faster loading phase of about 0.3 g/kg a day for 5–7 days also works but isn’t necessary. Monohydrate is the form most of the research uses.
Expect the scale to creep up a little. In that review, body mass typically rose 1–2 kg more than in control groups over 4–12 weeks of training. That’s expected, so judge your cut by your waist, photos and lifts as well as the scale.
Caffeine: useful, but count every source
Caffeine is the best-supported stimulant for training. The ISSN’s 2021 position stand says 3–6 mg per kilogram of body weight, usually taken about 60 minutes before exercise, consistently improves performance, and that doses as low as 2 mg/kg may work. Very high doses, around 9 mg/kg, bring a high rate of side effects and don’t appear necessary for a benefit.
Its main value during a cut is helping you train hard when food is lower, not burning fat directly. Here’s the catch: for a 90 kg (198 lb) man, 3–6 mg/kg is 270–540 mg. The FDA says up to 400 mg a day is not generally associated with negative effects for most healthy adults, and that total includes coffee, energy drinks, pre-workouts and fat burners.
So start at the low end, skip caffeine late in the day if it affects your sleep, and talk to your doctor first if you have heart problems, high blood pressure or anxiety, or take medication. If you’d rather avoid stimulants, see our guide to stim-free pre-workouts.
Optional extras with smaller or uncertain effects
Beta-alanine
The ISSN’s beta-alanine position stand says 4–6 g a day for at least 2–4 weeks raises muscle carnosine, which helps buffer acid during hard efforts. Benefits are clearest in efforts lasting about 1–4 minutes, and more research is needed on strength. The only reported side effect is a tingling feeling (paresthesia), which smaller split doses of about 1.6 g or a sustained-release form can reduce.
It’s most relevant if your training includes circuits, conditioning or high-rep sets. It works through daily use, not a single scoop before training.
HMB
HMB is made in the body from the amino acid leucine. The ISSN’s 2018 review placed HMB in its strongest category for muscle building, but rated the evidence for performance as mixed. Benefits appear most reliably in untrained people, while results in trained lifters are less clear. Studies typically use 3 g a day, split into three 1 g doses. If you already take protein and creatine, it’s a low priority.
Green tea extract
According to NCCIH, green tea’s catechins and caffeine may have a modest effect on body weight, but conclusions aren’t definite. Liver injury has been reported in some people who used green tea products, and green tea can interact with medications, including the blood pressure drug nadolol and the statin atorvastatin. If you use an extract, count its caffeine and stop it if you notice signs of liver trouble, such as yellowing skin or eyes or dark urine. Our guide to how fat burners actually work explains why most thermogenic effects are small.
Ashwagandha
NCCIH says some ashwagandha preparations may help with stress and insomnia. It doesn’t appear in the ISSN’s 2018 list of supplements with strong evidence for building muscle, and NCCIH notes only limited evidence that it may modestly raise testosterone; claims of dramatic cortisol or testosterone changes go beyond that.
Safety matters here. Liver injury is rare but has been reported. NCCIH says it isn’t recommended for people with thyroid or autoimmune disorders or before surgery, and that people with hormone-sensitive prostate cancer should avoid it. It may also interact with diabetes, blood pressure and thyroid medications, sedatives and immunosuppressants.
L-carnitine and CLA
These are popular in fat burners, but the evidence is weak. The ISSN’s review says most data show carnitine doesn’t markedly change muscle carnitine, fat metabolism, performance or weight loss. For CLA, it says human studies suggest at best a modest effect on fat loss, with little evidence that it helps you build lean tissue. Your money is better spent on food and the basics above.
Yohimbine: why we don’t recommend it for most people
Yohimbine, from the bark of the yohimbe tree, is marketed for “stubborn” fat. The evidence doesn’t support the hype: NCCIH says there isn’t enough evidence to reach definite conclusions about yohimbe’s effectiveness for any health condition.
The risks are well documented. Yohimbine has been associated with irregular heartbeat, blood pressure problems, heart attacks and seizures. A review of poison control reports found stomach problems, rapid heartbeat, anxiety and high blood pressure. Dosing is also unreliable, because most yohimbe products don’t state how much yohimbine they contain, and amounts vary widely between brands.
A sensible stack for cutting and recomp
| Priority | Supplement | Research-based amount | Notes |
|---|---|---|---|
| Foundation | Protein (food first, powder if needed) | 1.6–2.2 g/kg/day total | Spread across your meals |
| Foundation | Creatine monohydrate | 3–5 g/day | Take it every day, including rest days |
| Optional | Caffeine | Start around 2–3 mg/kg before training | Keep your daily total from all sources within 400 mg |
| Optional | Beta-alanine | 4–6 g/day in split doses | Only if you do lots of 1–4 minute efforts |
| Low priority | HMB | 3 g/day (3 × 1 g) | Most useful for newer lifters |
| Skip | L-carnitine, CLA | Not recommended | Weak evidence |
| Avoid unless a doctor approves | Yohimbine | Not recommended | Heart rhythm, blood pressure and anxiety risks |
What this looks like in practice
Take a hypothetical 90 kg (198 lb) man who lifts four days a week and wants to lose fat while keeping his strength.
- Calories: he estimates his maintenance with a calculator and eats a modest amount below it, adjusting after a few weeks based on his weekly average weight.
- Protein: 1.6–2.2 g/kg is 144–198 g a day. He aims for about 160 g: four meals with 35–40 g each, plus a shake on busy days.
- Creatine: 5 g every morning, training day or not.
- Caffeine: 2–3 mg/kg is 180–270 mg. He checks his labels and finds that his pre-workout, two coffees and a fat burner add up to more than 400 mg, so he drops the fat burner.
- Tracking: weekly average weight, waist measurement and his main lifts every two to four weeks.
He ends up with two foundation supplements and one optional one, chosen for clear reasons. For a wider view of fat burners and how their ingredients compare, see our thermogenics ranked by efficacy and safety.
Common mistakes to avoid
Stacking stimulants without adding them up
Pre-workouts, fat burners, energy drinks and coffee all count toward the same daily total. Check every label before you combine them.
Buying proprietary blends
Blends hide individual doses, so you can’t compare them with the research. Choose fully disclosed labels.
Cutting protein along with calories
When calories drop, protein is the part of your diet to protect. Hitting your target matters more than any recomp supplement.
Expecting a fat burner to do the work
No supplement makes up for an inconsistent deficit or half-hearted training. The effects of most fat-loss ingredients are small.
Taking beta-alanine only before workouts
Its benefits come from daily intake over weeks. An occasional small scoop is unlikely to match what the studies used.
Panicking about early creatine weight
A small rise on the scale is expected. Look at your waist and strength before deciding your cut has stalled.
Who should check with a doctor first
- Anyone with heart disease, an irregular heartbeat or high blood pressure, especially before using caffeine-heavy products.
- Anyone with kidney or liver disease.
- Anyone with anxiety or panic disorder, or a thyroid or autoimmune condition.
- Anyone who takes prescription medication, including antidepressants, blood pressure, diabetes or thyroid drugs.
- Anyone under 18.
