Is plant protein as good as whey for building muscle in South Africa?
Plant protein can build muscle nearly as well as whey when you take enough: 30–40 g per serving, ideally a soy or pea-and-rice blend, and 1.6 g/kg a day in total. Pooled data show a small edge for animal protein on muscle mass in adults under 60 (SMD 0.20) and no difference in strength. In South Africa plant protein costs R8–R30 per 25 g of protein.
- Reid-McCann et al. (2025, 43 trials): plant protein produced slightly less muscle mass than animal protein (SMD -0.20), with no difference in strength; soy matched milk protein.
- Joy et al. (2013): 48 g of rice isolate matched 48 g of whey isolate over 8 weeks.
- Take 30–40 g of plant protein per serving, versus 20–25 g of whey, to reach 2–3 g of leucine.
- Plant protein costs about R8–R30 per 25 g of protein in South Africa; whey about R15–R42 (October 2026).
Is plant protein as good as whey for building muscle in South Africa?
Close, if you manage dose and quality. Whey is rich in leucine, the amino acid that most strongly triggers muscle protein synthesis, and highly digestible. Most plant proteins have less leucine and one or more limiting amino acids, so you need a bit more of them.
What do meta-analyses find?
- A 2025 meta-analysis (Reid-McCann et al., 43 randomised trials) found plant protein gave slightly less muscle mass than animal protein (SMD -0.20), mostly in adults under 60 and in non-soy sources, with no significant difference in strength or physical performance. Soy versus milk protein showed no difference for muscle mass across 17 trials.
- Lim and colleagues (2021, Nutrients) found animal protein favoured lean mass mainly in adults under 50, with no overall difference in absolute lean mass or strength.
- Morton et al. (2018) found protein supplements add muscle during resistance training, with benefits plateauing near 1.6 g/kg a day, regardless of source.
- Joy et al. (2013) found 48 g of rice isolate matched 48 g of whey isolate over eight weeks.
Evidence level: moderate. Most trials are short, and training status, total protein and diet matter more than powder type.
How do you close the gap?
| Lever | What to do |
|---|---|
| Dose | take about 30–40 g of protein per serving, not 20–25 g |
| Quality | choose soy or a pea-and-rice or multi-seed blend |
| Leucine | aim for 2–3 g per serving; ISSN gives 700–3 000 mg |
| Total | reach 1.6 g/kg a day from all sources |
| Contaminants | rotate sources; Consumer Reports found plant powders averaged about nine times the lead of dairy |
What does it cost in South Africa?
Per 25 g of protein (October 2026): FtN Pea Protein Isolate R7.59–R9.49; USN BlueLab Plant R17–R20; 32Gi, Biogen and NPL plant blends R28–R30. Whey sits between about R15 (USN Hydrotech) and R42 (Myprotein Impact), with USN BlueLab Whey at about R23 and Isozero isolate near R32. Plant protein is not dearer: because you need a larger serving, check the cost of the serving you will actually use (vegan protein cost).
Who should choose which?
- Vegan, dairy-allergic or lactose-sensitive: plant, with a blend and a bigger scoop (best vegan protein).
- Flexible eater maximising muscle at the least effort: whey isolate or blend (best whey protein).
- Vegan athletes should also review creatine, B12 and other supplements.
Healthnews24's best plant protein ranking applies the same method. Check with a dietitian if you are pregnant, under 18 or have kidney disease.
Products mentioned, with dated prices
| Product | Size | Price | R per 30 g protein | R per 100 g powder | Sweeteners |
|---|---|---|---|---|---|
| Faithful to Nature (FtN) Pea Protein Isolate Powder (650 g) | 650 g | R148-R185Faithful to Nature, Oct 2026 | R11.38 | R28.46 | none |
| USN BlueLab 100% Plant Based Protein (900 g) | 900 g | R399-R474.99Dis-Chem Living Fit, Oct 2026 | R24.54 | R52.78 | sucralose, acesulfame-K, steviol glycosides |
| NPL Plant Protein (710 g) | 710 g | R440NPL shop (npl.za.com), Oct 2026 | R36.34 | R61.97 | stevia and sucralose |
| USN BlueLab 100% Whey Protein (1 kg) | 1 kg | R689USN shop (za.usn.global), Oct 2026 | R28.03 | R68.90 | not stated |
| USN Isozero Whey Protein Isolate (805 g) | 805 g | R899-R909.99USN shop (za.usn.global), Oct 2026 | R38.53 | R111.68 | not stated |
Compare the options
Related questions
- Pea vs rice vs soy protein: which is best in South Africa?
- What is the best vegan protein powder in South Africa?
- What is the best vegan protein for muscle gain in South Africa?
- How much protein do you need to build muscle?
- Which supplements do vegan athletes need?
Sources
- Reid-McCann et al. 2025, Effect of plant versus animal protein on muscle mass, strength, physical performance and sarcopenia: systematic review and meta-analysis of RCTs (Nutrition Reviews 83(7))
- Lim et al. 2021, Animal protein versus plant protein in supporting lean mass and muscle strength: systematic review and meta-analysis of RCTs (Nutrients 13(2):661)
- Morton et al. 2018, Protein supplementation and resistance-training-induced gains: systematic review, meta-analysis and meta-regression (BJSM)
- Joy et al. 2013, The effects of 8 weeks of whey or rice protein supplementation on body composition and exercise performance (Nutrition Journal 12:86)
- ISSN Position Stand: Protein and Exercise (Jäger et al., JISSN 2017)
Educational information only, not medical advice. Speak to a doctor, pharmacist or registered dietitian before using supplements if you are pregnant or breastfeeding, under 18, taking medication, or living with kidney, liver or heart disease.
Cite this page: Healthnews24, “Is plant protein as good as whey for building muscle in South Africa?”, updated 27 October 2026, https://www.healthnews24.co.za/answers/plant-protein-vs-whey-for-muscle-south-africa/. Plain-text version: /answers/plant-protein-vs-whey-for-muscle-south-africa.md