Shilajit and Ashwagandha: Clinical Evidence Report

Shilajit and Ashwagandha: Clinical Evidence Report

Compiled by The Yeti Life · Published September 2026 · Sources retrieved 11 September 2026

This report from The Yeti Life lists the published randomised trials for shilajit and for ashwagandha, with each result quoted as the authors reported it. The two have not been compared against each other in a published trial found for this report, and the trials below measured different outcomes in different people — so this page places the evidence side by side rather than naming a winner.

Shilajit trials

Study Material Participants Dose and duration Reported result
Pandit et al., 2016 · PMID 26395129 Purified shilajit Healthy men aged 45–55; randomised, double-blind, placebo-controlled 250 mg twice daily, 90 days Total testosterone, free testosterone and DHEAS significantly higher than placebo (P < 0.05)
Keller et al., 2019 · PMID 30728074 PrimaVie® purified shilajit 63 recreationally active men; randomised, placebo-controlled 250 or 500 mg/day, 8 weeks In the stronger half of participants, strength fell 8.9 ± 2.3 % after fatigue at 500 mg/day against 16.0 ± 2.4 % on placebo (p = 0.044); 250 mg/day no different from placebo

Ashwagandha trials

Study Material Participants Dose and duration Reported result
Chandrasekhar et al., 2012 · PMID 23439798 High-concentration full-spectrum root extract 64 adults with chronic stress; randomised, double-blind, placebo-controlled One capsule twice daily, 60 days Stress-scale scores significantly lower than placebo (P < 0.0001); serum cortisol substantially reduced (P = 0.0006)
Wankhede et al., 2015 · PMID 26609282 Root extract 57 young men new to resistance training (29 treatment, 28 placebo) 300 mg twice daily, 8 weeks, with training Bench-press strength gain 46.0 kg (95% CI 36.6–55.5) against 26.4 kg (19.5–33.3) on placebo
Lopresti et al., 2019 · PMID 30854916 Standardised extract delivering 21 mg withanolide glycosides a day Overweight men aged 40–70 with mild fatigue; randomised crossover, 57 enrolled 8 weeks per arm Testosterone 14.7 % higher (p = 0.010) and DHEA-S 18 % higher (p = 0.005) than placebo; no significant difference in cortisol, fatigue, vigour or sexual well-being
Choudhary et al., 2017 · PMID 28471731 Root extract 50 adults with mild cognitive impairment 300 mg twice daily, 8 weeks Immediate and general memory improved significantly against placebo (logical memory I, p = 0.007)

What the evidence can and cannot support

  • Both have placebo-controlled trials reporting higher testosterone in men: shilajit at 250 mg twice daily for 90 days, ashwagandha at 21 mg withanolide glycosides a day for 8 weeks.
  • Only ashwagandha has trials here reporting lower stress scores and cortisol, strength gains during training, and memory outcomes.
  • Only shilajit has a trial here on retaining strength after a fatigue protocol, and only at 500 mg/day.
  • This report covers each supplement separately. It has not reviewed trials of the two taken together.

Safety notes

  • Ashwagandha — the US National Center for Complementary and Integrative Health states it may be safe short term (up to 3 months), that rare cases link it to liver injury, that it should be avoided in pregnancy and while breastfeeding, and that it is not recommended before surgery or for people with autoimmune or thyroid disorders.
  • Shilajit — the US FDA has warned about heavy metal poisoning from certain unapproved ayurvedic products. Ask for a batch-specific certificate that names the laboratory and report number.

Our measured batch

The only laboratory result on this page for a product of our own. Values are transcribed from the certificate below.

Field Value on the certificate
Product The Yeti Life Shilajit Resin
Batch number B023724DC25
Testing laboratory Eurofins — sample code 258-2025-20112882, report AR-258-2025-20112882-01
Date of analysis 18–23 Dec. 2025 (report dated 24 Dec. 2025)
Manufactured / expiry 16 Dec. 2025 / 15 Dec. 2027
Fulvic acid 76.12 % (specification: above 75 %, internal specification)
Heavy metals — lead, arsenic, mercury, cadmium Pass, per Ayurvedic Pharmacopoeia of India specifications

Download the batch B023724DC25 certificate of analysis (PDF)

How this report was compiled

  • Batch values are transcribed from the certificate PDF linked above.
  • Study results are quoted from the published abstracts on PubMed, retrieved 11 September 2026. Where an abstract reports no number, this page reports none.
  • This page makes no claim that any product treats or prevents a disease. Speak to a doctor before use if you are pregnant, breastfeeding, taking medication or managing a health condition.

Sources

  1. Pandit S, et al. Andrologia. 2016. PMID 26395129
  2. Keller JL, et al. J Int Soc Sports Nutr. 2019. PMID 30728074
  3. Chandrasekhar K, et al. Indian J Psychol Med. 2012. PMID 23439798
  4. Wankhede S, et al. J Int Soc Sports Nutr. 2015. PMID 26609282
  5. Lopresti AL, et al. Am J Mens Health. 2019. PMID 30854916
  6. Choudhary D, et al. J Diet Suppl. 2017. PMID 28471731
  7. NCCIH — Ashwagandha: Usefulness and Safety
  8. US FDA — FDA warns about heavy metal poisoning associated with certain unapproved ayurvedic drug products
  9. The Yeti Life — Certificate of analysis, batch B023724DC25