Evidence at a glance
One randomised trial on strength retention, plus one muscle gene-expression study. How ratings work: evidence rating system.
The exercise trial in detail
| Feature | Detail |
|---|---|
| Participants | Recreationally active men[1] |
| Design | Randomised, placebo-controlled; 250 mg or 500 mg a day |
| Duration | 8 weeks |
| Test | Maximal strength before and after a fatiguing exercise protocol |
| Main finding | The 500 mg group retained more strength after fatigue |
| Product | A standardised branded extract |
The muscle gene-expression study
A 2016 study took muscle biopsies from overweight adults before and after supplementation and found changes in genes linked to muscle structure.[2] It shows biological activity in muscle, but it didn’t measure strength, size or performance. See gene-expression research.
What hasn’t been measured
- Muscle growthNo study measured muscle size or mass.
- Endurance performanceRunning or cycling performance hasn’t been tested.
- RecoverySoreness and recovery time haven’t been studied directly.
- Women and older adultsThe trial included men only.
Advice for athletes and gym users
If you compete in drug-tested sport, any supplement carries a risk of contamination with banned substances. UK Anti-Doping advises using batch-tested products and checking them before use.[3] Shilajit itself isn’t a banned substance, but the product you buy needs to be clean. See shilajit, sport and anti-doping. For performance, training, nutrition and sleep matter far more than any supplement with one small trial behind it.
About the dose
The benefit appeared at 500 mg a day of a specific standardised extract; the 250 mg group didn’t show the same effect.[1] A different resin at a different serving isn’t the same intervention, so results can’t be assumed for other products; see why preparation and dose matter and how to use shilajit.
Exercise claims and UK rules
“Builds muscle”, “boosts performance” and “speeds recovery” are health claims under UK advertising rules, and the ASA has published advice treating muscle and performance claims for supplements this way.[4] They need authorised wording. Protein has authorised claims about muscle; shilajit doesn’t.[5]
What “strength retention after fatigue” means
In the trial, participants performed a test of maximal strength, then a demanding exercise protocol designed to tire the muscles, then the strength test again. The question was how much strength they kept after fatigue. The higher-dose group kept more.[1] That is relevant to repeated efforts in training, but it isn’t the same as getting stronger over time or building muscle.
What would strengthen the evidence
Independent replication, women and older adults as participants, longer training studies measuring muscle size and strength gains, and tests of different shilajit products would all help. Until then, exercise rates “Limited”.
Where shilajit fits in a training plan
For strength and muscle, progressive training, adequate protein and energy intake, and sleep have strong evidence. Creatine is one of the best-researched sports supplements. Compared with these, shilajit has one small trial. If you add shilajit, make it the last consideration, not the first, and keep a training log so you can judge any change honestly. Competitive athletes should check products carefully before use, as UK Anti-Doping advises.[3]
Women who train
The trial included men only, so women who train can’t assume the same result. The same principles apply: training, nutrition and sleep first, and a batch-tested product if you try shilajit.
The bottom line
Shilajit has one encouraging exercise trial, showing better strength retention after fatigue at 500 mg a day of one extract. That is far from evidence that it builds muscle or improves performance. Athletes should prioritise training and nutrition and, if they try shilajit, use a batch-tested product.
Frequently asked questions
Does shilajit build muscle?
No study has measured muscle growth. One trial found better strength retention after fatigue.[1]
Does shilajit improve strength?
In one 8-week trial, men taking 500 mg a day retained more strength after a fatiguing test than those on placebo.[1]
Is shilajit allowed in sport?
It isn’t a banned substance, but products can be contaminated. UK Anti-Doping advises batch-tested products.[3]
Should I take shilajit before the gym?
No study has tested timing around workouts.
Does shilajit help recovery?
Recovery hasn’t been studied directly.
Does shilajit work for women who train?
Unknown; the trial included men only.
Is shilajit better than creatine or protein?
No study has compared them. Protein has authorised muscle claims; shilajit doesn’t.[5]
How long did the shilajit exercise trial last?
Eight weeks.[1]
Is resin as effective as the extract used in the trial?
Unknown. The trial used a standardised extract, and other products may differ.
Does shilajit help older adults keep muscle?
Not studied. The trial included active men, not older adults.
Does shilajit increase testosterone in athletes?
The exercise trial didn’t focus on testosterone. See testosterone for the separate trial.
Can shilajit replace pre-workout supplements?
No study has compared them, and shilajit hasn’t been tested as a pre-workout.
Does shilajit reduce muscle soreness after exercise?
Not studied directly. The trial measured strength retention after fatigue, not soreness.[1]
Is shilajit worth it for bodybuilders?
There is no evidence that it builds muscle. Training, protein and recovery have far stronger evidence.
Does shilajit improve endurance for running or cycling?
Endurance performance hasn’t been tested. The trial measured strength retention after a fatiguing protocol.[1]
Sources & further reading
Primary research, regulators and standards bodies are cited first. A source being listed here does not mean it supports every claim made by sellers; it supports the specific statement it is attached to.
- Keller JL, Housh TJ, Hill EC, Smith CM, Schmidt RJ, Johnson GO. The effects of Shilajit supplementation on fatigue-induced decreases in muscular strength and serum hydroxyproline levels. Journal of the International Society of Sports Nutrition 16:3, 2019. doi:10.1186/s12970-019-0270-2; PMID 30728074. View source (opens in a new tab) [Randomised controlled trial]
- Das A, et al.. The human skeletal muscle transcriptome in response to oral Shilajit supplementation. Journal of Medicinal Food 19(7):701–709, 2016. doi:10.1089/jmf.2016.0010; PMID 27414521. View source (opens in a new tab) [Human study (gene expression)]
- UK Anti-Doping (UKAD). Clean Sport Essentials pocket guide. ukad.org.uk, 2021. View source (opens in a new tab) [Anti-doping guidance]
- Advertising Standards Authority / CAP. Food: sports supplements and associated products (advice). asa.org.uk. View source (opens in a new tab) [Advertising regulator advice]
- Department of Health and Social Care. Great Britain nutrition and health claims (NHC) register. GOV.UK. View source (opens in a new tab) [Official register]