What is Ashwagandha?

Ashwagandha, also known as Withania somnifera is a shrub used in Ayurveda to support the nervous system. Most supplements ion the market containing Ashwagandha will contain the standardise bioactive withanolides, most commonly from the root (e.g., KSM‑66®) or root + leaf (e.g., Sensoril®, Shoden®). Extracts can differ in withanolide profile, dose and bioavailability, so follow the product label rather than assuming extracts are interchangeable.

Australian context (TGA & product quality)

In Australia, ashwagandha supplements are regulated as complementary medicines. Choose TGA‑listed products (look for an AUST L number on pack) from reputable retailers. The Therapeutic Goods Administration (TGA) has issued a safety advisory noting very rare reports of liver injury and gastrointestinal effects. Make sure to speak with a GP, pharmacist or health practitioner before use.

Mental and Cognitive Benefits

Reduces stress and anxiety:
Research has shown that ashwagandha can help lower stress and anxiety, often alongside reductions in cortisol. Most studies see results after 6–12 weeks when using standardised root extracts (around 240–600 mg per day, depending on the product).

Improves sleep:
Clinical trials show that ashwagandha can improve overall sleep quality- helping you fall asleep faster and increase total sleep time. The benefits are usually modest and build gradually over a few weeks.

Supports cognitive function:
Early studies suggest small but positive improvements in attention, memory, and overall mental clarity—especially in people dealing with stress or poor sleep. Results in young, healthy adults are mixed and still evolving.

Physical health benefits

Improves physical performance:
Several studies and meta-analyses show gains in muscle strength, power, endurance (VO₂max) and post workout recovery, typically when taking around 300 mg of root extract twice daily for 8–12 weeks alongside regular training. Results can vary depending on the extract and training program.

Supports male reproductive health:
Studies in both fertile and infertile men report improvements in sperm count, motility and semen volume, with some showing increases in testosterone after 8–12 weeks of use. The findings are encouraging but vary across studies, and any fertility concerns should still be checked by a healthcare professional.

Helps support hormone balance:
Ashwagandha influences several hormone pathways, which may contribute to improved mood and sleep benefits. However, it can affect thyroid hormones in some people, so anyone with thyroid conditions should seek medical advice before using it.

Supports heart health:
Early research suggests Ashwagandha may help blood vessels function better, but larger, high-quality studies are still needed.

May help with blood sugar:
Preliminary evidence points to potential improvements in fasting glucose and insulin sensitivity, but strong clinical trials are limited. People taking diabetes medication should not adjust their dose without medical guidance.

How to take Ashwagandha (Australia)

Common doses used:

• KSM‑66® (root): 300 mg twice daily (total 600 mg/day).
  
• Other standardised extracts (Sensoril®, Shoden®, etc.): 120–500 mg/day depending on standardisation—follow the label; extracts are not 1:1 interchangeable.

When to take: With food to minimise gastrointestinal upset; evening dosing can suit sleep‑focused users (based on trial timing).

Duration: Most benefits are studied over 6–12 weeks; long‑term data are limited—periodic breaks are sensible.

Safety, side effects & who should avoid it (Australia)

• Generally well‑tolerated short‑term in RCTs (up to 8–12 weeks). Mild GI symptoms, drowsiness or headache are the most common effects.
  
• Rare liver‑injury reports: TGA notes very rare cases. People with liver disease should avoid use unless medically supervised; discontinue if jaundice, dark urine or severe fatigue occur.
  
• Thyroid concerns: case reports and risk assessments flag possible effects on thyroid hormones—avoid if hyperthyroid or with unstable thyroid disease unless advised by your doctor.
  
• Pregnancy & breastfeeding: not recommended due to insufficient safety data.
  
• Interactions: caution with sedatives, thyroid medicines, anti-diabetics and immunosuppressants—consult a healthcare professional.

Important considerations

Varying effects: Response differs by extract type, dose, standardisation and participant profile (stressed, athletic, sleep‑disturbed, etc.). Choose products with clear withanolide standardisation and follow evidence‑based dosing.

Scientific evidence: Strongest signals are for stress/anxiety and sleep; sports performance, male fertility and cognition are encouraging but variable; endothelial and glycaemic outcomes remain preliminary.

Consult a doctor: Essential if you’re pregnant, breastfeeding, have thyroid or liver disease, take prescription medicines or plan to use ashwagandha for a diagnosed condition.

FAQs

Q: Is ashwagandha legal in Australia?

A: Yes. It’s available as a TGA‑listed complementary medicine. Choose brands with an AUST L number on pack.

Q: How long before I feel a difference?

A: Most sleep and stress studies report benefits from 2–6 weeks, with further gains by 8–12 weeks.

Q: KSM‑66 vs Sensoril vs Shoden, what’s the difference?

A: They differ by plant part (root vs root+leaf), withanolide chemistry, dose and bioavailability. Follow the specific product’s dose; do not assume equivalence.

Q: Can athletes use it?

A: Trials suggest gains in strength, VO₂max and recovery with 8–12 weeks of standardised extract alongside training. Always check your sport’s supplement policy and batch testing.

Q: Does it raise testosterone?

A: Some studies, especially in men with subfertility, observed increases in testosterone alongside improved semen parameters; results in healthy men are less consistent.

References

Therapeutic Goods Administration (Australia). Medicines containing Withania somnifera (Ashwagandha) — Safety advisory. https://www.tga.gov.au/safety/safety-monitoring-and-information/safety-alerts/medicines-containing-withania-somnifera-withania-ashwagandha

Kumar S, et al. Effect of Ashwagandha extract on sleep: A systematic review and meta‑analysis of randomised controlled trials. PLOS ONE. 2021;16(9):e0257843. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0257843

Wong JY, et al. Effects of ashwagandha supplements on cortisol, stress and anxiety in adults: Systematic review and meta‑analysis. BJPsych Open. 2025. https://doi.org/10.1192/bjo.2024.123 

Cicero AFG, et al. Effects of Withania somnifera on VO₂max: Systematic review and meta‑analysis. Nutrients. 2020;12(4):1119. https://www.mdpi.com/2072-6643/12/4/1119

Ambiye VR, et al. Clinical evaluation of Ashwagandha root extract in oligospermic males: Randomised placebo‑controlled study. Evid Based Complement Alternat Med. 2013;2013:571420. https://onlinelibrary.wiley.com/doi/pdf/10.1155/2013/571420

Satpathy S, et al. Ashwagandha root extract and male sexual health: Randomised, double‑blind, placebo‑controlled trial (8 weeks). 2025. (ScienceDirect record) https://www.sciencedirect.com/science/article/pii/S0975947625000312

Deshpande A, et al. Ashwagandha extract for non‑restorative sleep: Randomised, double‑blind trial. Sleep Med. 2020;72:28‑35. https://www.sciencedirect.com/science/article/abs/pii/S1389945720301246

Food Standards Agency (UK). Ashwagandha: risk assessment summary (thyroid, glycaemic, liver signals). 2024. https://www.food.gov.uk/print/pdf/node/23791

Sudarshan S, et al. Ashwagandha’s multifaceted effects on human health, including endothelial outcomes. Nutrients. 2023;16(15):2481. https://www.mdpi.com/2072-6643/16/15/2481

Rai M, et al. Herbal medicines and male reproductive system: Evidence synthesis (includes Withania). Integr Med Res. 2024. https://www.sciencedirect.com/science/article/pii/S2667142524001040

Narrative review: Antidiabetic potential of ashwagandha. J Herb Med. 2024. https://www.sciencedirect.com/org/science/article/abs/pii/S1478641924009525

Shah D, et al. Salivary hormones and vitality after ashwagandha: Randomised, double‑blind, crossover trial in healthy overweight men. Am J Mens Health. 2019. https://journals.sagepub.com/doi/pdf/10.1177/1557988319835985