A comprehensive overview of 11 systematic reviews, encompassing data from over 9,000 individuals, provides robust evidence for the multifaceted benefits of Ashwagandha (Withania somnifera) ^[1]. This powerful adaptogen demonstrates significant efficacy in enhancing both physical performance and key health-related outcomes. The findings position Ashwagandha as a well-supported supplement for improving muscular strength, endurance, sleep quality, and resilience to stress.

Key Findings

This overview synthesized data from 151 original studies, revealing consistent patterns in the effects of Ashwagandha supplementation ^[1].

• Broad Efficacy: Supplementation was shown to improve multiple aspects of sports performance, including both endurance and muscular strength.
• Psychological and Health Benefits: Significant improvements were noted in health-related outcomes, including marked anxiety reduction, enhanced sleep quality, and improved sexual function.
• Effective Dosage: The most commonly studied and effective doses ranged between 500 mg and 1000 mg per day.

The Longevity Context

The benefits of Ashwagandha align directly with several core pillars of longevity science: stress modulation, physical capacity, and restorative sleep. Its classification as an adaptogen points to its ability to help the body maintain homeostasis, a critical function for healthy aging.

1. Stress and HPA Axis Regulation: Chronic stress elevates cortisol, dysregulating the hypothalamic-pituitary-adrenal (HPA) axis and accelerating aging processes. Ashwagandha appears to directly counter this. A 60-day randomized, double-blind, placebo-controlled study in stressed, healthy adults found that supplementation was associated with significant reductions in morning cortisol, suggesting a moderating effect on the HPA axis ^[2].

2. Physical Performance as a Longevity Biomarker: Cardiorespiratory fitness (VO₂ max) and muscular strength are two of the most potent predictors of lifespan and healthspan. A Bayesian meta-analysis concluded that Ashwagandha supplementation was more effective than placebo for improving variables related to physical performance in both men and women, including strength/power and cardiorespiratory fitness ^[3]. By enhancing these fundamental physical attributes, Ashwagandha supports the maintenance of a robust and resilient physiology.

3. The Critical Role of Restorative Sleep: Sleep is essential for cellular repair, glymphatic clearance in the brain, and hormonal regulation. Inadequate sleep is a potent driver of inflammation and metabolic dysfunction. Ashwagandha has demonstrated a profound ability to improve sleep quality. A randomized controlled trial found that subjects taking a standardized Ashwagandha extract for six weeks reported a 72% improvement in sleep quality, compared to just 29% in the placebo group. This subjective improvement was validated with objective actigraphy data showing significant enhancements in sleep efficiency, total sleep time, and the time taken to fall asleep ^[4].

Actionable Protocol

Based on the evidence, the following protocol can be considered for integrating Ashwagandha:

• Supplement: Use a standardized Ashwagandha (Withania somnifera) root extract. Standardization (e.g., to 5% withanolides) helps ensure consistent potency.
• Dosage: Start with 600 mg total per day, divided into two 300 mg doses. This falls within the effective 500-1000 mg range identified in the research.
• Timing: Take one dose in the morning and one in the evening with meals to support stable levels and enhance sleep quality.
• Caution: While generally well-tolerated, consult with a healthcare professional before beginning any new supplement regimen, as recommended by the review's authors.