Ashwagandha

WHAT IT DOES

• Reduces stress and cortisol — Strong evidence supports significant cortisol reduction and stress symptom improvement across 10+ RCTs. This is ashwagandha's most reliable benefit.
• Reduces anxiety symptoms — Grade A evidence from 10 studies (540 participants) shows moderate improvement in anxiety scores. Works in both clinical and subclinical anxiety.
• Improves sleep quality — Grade A evidence from 5 studies (1,764 participants). Most effective at 600mg/day, particularly in people with insomnia.
• Increases strength and power output — Grade A evidence. 5-10% improvement in strength metrics across 7 studies. Works in both trained and untrained adults.
• May increase testosterone — Grade B evidence from 4 studies (361 participants). Small but consistent increases, particularly relevant for infertile men or those with low baseline levels.
• Supports immune function — Increases lymphocytes, natural killer cells, and immunoglobulins at 60-1,000mg/day over 4-16 weeks.

OPTIMAL DOSAGE

DRUG INTERACTIONS

SAFETY PROFILE

Side Effects

• Common: Drowsiness (mild and transient), gastrointestinal symptoms (stomach upset, loose stools, nausea, vomiting)
• Rare: Liver toxicity (reported in several case reports but NOT confirmed by larger controlled studies — onset typically 2-12 weeks, resolves 1-3 months after stopping)
• Rare: Thyrotoxicosis (case reports only; larger studies did not observe thyroid hormone changes)

Drug Interactions

Precautions

• Pregnancy: Avoid. Safety not established in humans. Animal studies at high doses showed no adverse effects, but human data is lacking.
• Breastfeeding: Avoid. No human research available. Used traditionally in Ayurveda to promote lactation, but safety is unconfirmed.
• Children: No established pediatric dosing. Avoid unless directed by a healthcare provider.
• Organ transplant recipients: Avoid. Ashwagandha stimulates the immune system. One case report documented organ rejection in a stable kidney transplant recipient after starting ashwagandha.
• Thyroid conditions: Use with caution. May increase thyroid hormones — could worsen hyperthyroidism or alter hypothyroidism drug requirements.
• Autoimmune conditions: Use with caution. Immune-stimulating properties could theoretically worsen autoimmune diseases. One case report: a woman developed a new autoimmune condition after starting ashwagandha.
• Liver disease: Use with caution. Case reports link ashwagandha to liver toxicity (onset: 2-12 weeks; resolution: 1-3 months after discontinuation).
• Testosterone-sensitive conditions (prostate cancer): Avoid until more data is available. Ashwagandha may increase testosterone levels.
• Surgery: No specific data, but given sedative and blood glucose effects, consider stopping 2 weeks before surgery.

Quality Concerns

Different ashwagandha supplements contain widely varying amounts of withanolides, often without disclosing the intended amount on the label. Studies have occasionally found cadmium and lead levels exceeding allowed limits — though not consistently. Dose AI recommends choosing products with third-party testing (USP, NSF, or Dose AI verified).

WADA Status

Not Prohibited. Ashwagandha is not on the 2026 WADA List of Prohibited Substances.

WHO SHOULD BE CAREFUL

QUALITY CONCERNS

HOW SCAN DOSE SCORES THIS

CLINICAL REFERENCES