Leucine, BCAAs, whey and HMB are all sold for muscle, but they deliver 1, 3, 9 or 0 of the essential amino acids. That difference explains most of what the trials found.
This page compares them on mechanism, evidence and cost per useful dose.
Quick Answer: Leucine vs BCAA vs Whey vs HMB
Whey is the most complete option, supplying all 9 essential amino acids and about 2.7 g of leucine per 25 g of protein. Leucine alone is a signal without the building blocks. HMB is a leucine breakdown product; only about 5% of leucine becomes HMB, and added to whey for 12 weeks, the 2 gave equal gains.
Key Takeaways
- Whey supplies all 9 essential amino acids; leucine supplies just 1.
- A standard 2:1:1 BCAA blend is half leucine, 50% by weight.
- Only about 5% of the leucine you eat becomes HMB.
- Making 3 g of HMB would take roughly 60 g of leucine.
- Whey plus 1.5 g HMB matched whey plus 1.5 g leucine.
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The 4 Options Side by Side
The quickest way to compare them is by what each supplies. Building new muscle protein needs all 9 essential amino acids, so the second column matters most.
| Option | Essential amino acids supplied | What it does | Remedy's version |
|---|---|---|---|
| Leucine | 1 of 9 | Switches synthesis on | L-Leucine, 1000 mg per capsule |
| BCAAs, 2:1:1 | 3 of 9 | The same signal, at half the leucine | BCAA, 1000 mg per 2 capsules |
| Whey protein | All 9 | Signal plus building blocks | Chocolate Whey, 12 oz tub |
| HMB | 0, it is a leucine metabolite | Slows breakdown, raises synthesis | HMB, 1000 mg per capsule |
The wider leucine story is in how leucine works as a nutrient signal.
Leucine vs BCAAs
A BCAA product is leucine plus isoleucine and valine. In the usual 2:1:1 ratio half the weight is leucine, so our 1000 mg BCAA serving holds 500 mg of leucine, half a leucine capsule.
- Leucine capsule: 1000 mg of leucine.
- BCAA serving, 2 capsules: 500 mg leucine, 250 mg isoleucine, 250 mg valine.
- Shared limit: Neither supplies the other 6 essential amino acids.
- Evidence: 0 human studies measured synthesis after oral BCAAs alone.
That last point comes from a widely cited 2017 review.[1]Branched-chain amino acids and muscle protein synthesis in humans: myth or reality? — Journal of the International Society of Sports Nutrition (2017) View source The case is argued in full in our guide to what BCAAs are.
Leucine vs Whey
Whey is the benchmark the leucine studies measure against. In young men, 6.25 g of whey topped up with leucine matched 25 g of whey early on. Only the full 25 g kept synthesis raised 3 to 5 hours after exercise.
- 25 g of whey protein: About 2.7 g of leucine plus all 9 essential amino acids.
- Collagen with added leucine: Built less muscle than whey over 10 weeks.
- Leucine-matched soy and whey: Built the same muscle over 12 weeks.
- The lesson: Leucine helps, but the rest of the protein matters too.
The collagen arm got 3.0 g of leucine, 2.0 g of it added free, yet whey grew thigh muscle thickness 8.4% against 5.6%.[2]Whey Protein Supplementation Is Superior to Leucine-Matched Collagen Peptides to Increase Muscle Thickness During a 10-Week Resistance Training Program — International Journal of Sport Nutrition and Exercise Metabolism (2022) View source
Why the extra building blocks matter over months is in the acute-versus-long-term gap.
Leucine vs HMB
HMB is made in the body from leucine, but only about 5% of leucine ends up as HMB. At that rate 1 leucine capsule yields roughly 50 mg of HMB, and the 3 g HMB dose used in trials would take about 60 g of leucine.
- Acute synthesis: 3.42 g of leucine raised it 110%; HMB raised it 70%.
- Breakdown: HMB cut muscle protein breakdown by 57%.
- Young lifters: A 2020 meta-analysis found no lean mass or strength gain.
- Older adults: A 2021 meta-analysis found more fat-free mass, though not with exercise.
The 5% figure is from the 2025 ISSN position stand.[3]International society of sports nutrition position stand: beta-hydroxy-beta-methylbutyrate (HMB) — Journal of the International Society of Sports Nutrition (2025) View source The 110% and 70% came from 1 tracer study.[4]Effects of leucine and its metabolite beta-hydroxy-beta-methylbutyrate on human skeletal muscle protein metabolism — Journal of Physiology (2013) View source
Head to head, 1.5 g of HMB or of leucine added to whey twice daily gave equal gains over 12 weeks.[5]Equivalent Hypertrophy and Strength Gains in beta-Hydroxy-beta-Methylbutyrate- or Leucine-supplemented Men — Medicine and Science in Sports and Exercise (2019) View source
Cost Per Gram, From Our Own Labels
Price per useful dose is a fair way to compare them. These are our list prices on 8 October 2026; they will change, but the arithmetic will not.
| Product | Price | Per bottle | Cost |
|---|---|---|---|
| L-Leucine 1000 mg, 60 capsules | $17.99 | 60 g of leucine | About $0.30 per g of leucine |
| BCAA 1000 mg, 30 servings | $29.99 | 15 g of leucine | About $2.00 per g of leucine |
| HMB 1000 mg, 60 capsules | $23.99 | 60 g of HMB | About $1.20 per 3 g trial dose |
Whey is left out because a scoop delivers protein, not a single measured compound.
Which One Fits Which Goal
Choose by the gap you are trying to fill. For most people the gap is total protein, which whey or food fills best. A single amino acid only makes sense when protein is already close.
- Short on protein: Whey or food first.
- Meal slightly short on leucine: A 1 g leucine top-up.
- Older and not exercising: HMB has the more favourable meta-analysis.
- Training on enough protein: None of the 4 is likely to add much.
Of the 4, single-ingredient L-leucine is the narrowest tool: 1 g of 1 amino acid.
Speak to a Clinician Before Taking Leucine If
- You have maple syrup urine disease or any other disorder of leucine metabolism
- You take insulin or another medicine that lowers blood sugar
- You have kidney or liver disease, or follow a protein-restricted diet
- You are pregnant or breastfeeding, where no leucine supplement trials exist
- You are buying it for a child or a teenager
Frequently Asked Questions
What are the benefits of taking leucine and HMB together? +
No trial shows a clear extra benefit from stacking them. Added to whey twice daily, 1.5 g of HMB and 1.5 g of leucine gave equal muscle and strength gains over 12 weeks.
How much HMB should I take? +
Trials and the 2025 ISSN position stand centre on 3 g a day, or 38 mg per kg. That is 3 of our 1000 mg HMB capsules.
Is HMB better than creatine? +
We have no head-to-head trial in our sources. HMB's record in young lifters is weak: a 2020 meta-analysis of 11 studies found no gain in lean mass or strength.
Can you take creatine and HMB together? +
We found 0 safety signals for combining them. The ISSN review found HMB well tolerated for up to 1 year; ask your clinician if you take other medicines.
Is HMB hard on kidneys? +
The ISSN position stand found chronic HMB intake safe for up to 1 year in humans. People with kidney disease were not its focus, so ask first.
How long does it take for HMB to kick in? +
Trials measured body composition after 4 to 12 weeks. A single dose raised muscle protein synthesis within hours in 1 tracer study.
When is the best time to take HMB and leucine? +
The ISSN stand notes HMB near exercise may help synthesis. Leucine studies gave it with meals; neither has a proven best hour, so take 1 dose with a meal.
Is leucine better than BCAA? +
Per gram of leucine, yes: 1 g of leucine is 1 g, while 1 g of 2:1:1 BCAA holds 0.5 g. Neither replaces whole protein.
Is whey better than leucine? +
For building muscle, yes. 25 g of whey supplies about 2.7 g of leucine plus all 9 essential amino acids, and only full whey kept synthesis raised 3 to 5 hours after training.
How much leucine is in a BCAA supplement? +
In a 2:1:1 blend, half the BCAA weight is leucine. Our BCAA product gives 500 mg of leucine per 2-capsule serving, half of 1 leucine capsule.
Related Reading
- Leucine-Rich Foods and the Meal Threshold
- Sarcopenia Trials of Leucine, Whey and HMB
- Planning a Leucine Dose Around Meals
- Is Leucine Safe Every Day?
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