Ashwagandha

Ashwagandha has good clinical evidence for reducing stress/anxiety and lowering cortisol, and plausible neurobiological mechanisms that could help PTSD symptoms, but human clinical evidence specifically in people with PTSD is very limited (mostly animal studies and indirect human trials).

• Adaptogen → lowers stress response / cortisol. Several randomized trials show ashwagandha reduces perceived stress and serum cortisol vs placebo — lowering cortisol and improving stress resilience is a core target in PTSD management. NHRI
• GABAergic / neurochemical effects and anti-inflammatory / neuroprotective actions. Preclinical and review literature describe ashwagandha constituents (withanolides) that modulate GABAergic signalling, reduce oxidative stress and inflammation, and support neuroprotection — these effects can plausibly reduce hyperarousal, anxiety and memory-related problems in PTSD. MDPI
• Evidence from animal PTSD models. In rodent PTSD models, oral ashwagandha/root powder prevented or reduced PTSD-like memory impairment and anxiety-like behaviors, supporting biological plausibility for direct benefits in PTSD. (Animal work is supportive but not proof for humans.) SpringerLink

Summary: the strongest, direct human evidence is for reducing stress/anxiety and cortisol (mechanistically relevant to PTSD). But direct evidence in clinical PTSD populations is scarce — most human RCTs recruited people with chronic stress or anxiety rather than diagnosed PTSD; animal PTSD models are promising but not definitive for humans. Office of Dietary Supplements

Formulation & extracts

• Most modern clinical trials use standardized root extract formulations (often standardized for withanolides). Common brands in trials include KSM-66 and other full-spectrum extracts. Trials usually report the extract amount (not raw powder). ScienceDirect

Typical trial dosages and schedules

• 300 mg twice daily (600 mg/day total) of a standardized extract is a commonly used and well-studied regimen in trials that showed reductions in stress/anxiety and cortisol (e.g., Chandrasekhar 2012 used 300 mg twice daily for 60 days). Other trials used 125 mg twice daily, 300 mg twice daily, or similar; many meta-analyses treat 300–600 mg/day as the practical range. NHRI
• Duration in trials is typically 6–12 weeks to see meaningful effects on perceived stress / anxiety. Some safety trials extended to 8–12 weeks and ongoing long-term safety trials exist. ScienceDirect+1

Administration

• Take with food (many trial protocols used oral capsules taken with meals).
• Use a standardized extract (label shows mg of extract and withanolide content) rather than unstandardized powders where possible.

Monitoring / integration with PTSD care

• Use alongside — not instead of — evidence-based PTSD treatments (trauma-focused psychotherapy, SSRIs where indicated). Monitor symptoms (PTSD checklist, anxiety, sleep, suicidal ideation) and consult prescriber for medication interactions. If symptoms are severe or suicidal, prioritize urgent psychiatric care.

Practical example regimen (trial-based):

• Ashwagandha extract 300 mg twice daily (morning + evening) for 8–12 weeks, re-evaluate symptom change and side effects with your clinician. This is the regimen most commonly used in stress/anxiety trials. NHRI

Key randomized controlled trials (human — stress/anxiety):

• Chandrasekhar K, Kapoor J, Anishetty S. (2012). A prospective, randomized, double-blind, placebo-controlled study… — 300 mg twice daily for 60 days; showed significant reduction in perceived stress and serum cortisol. (Indian J Psychol Med. 2012). NHRI
• Multiple RCTs (125–600 mg/day) showing anxiolytic/adaptogenic effects. Trial listings and PDFs summarizing several trials (e.g., double-blind 8-week trials with 125 mg or 300 mg twice daily arms) — see aggregated trial documents. tilpharma.com

Systematic reviews / meta-analyses:

• BJ Psych Open / Cambridge systematic review & meta-analysis (2024/2025 area). Recent systematic reviews/meta-analyses pooled RCT evidence and found significant effects of ashwagandha extracts on stress/anxiety and reductions in cortisol in adults. These analyses summarize multiple RCTs and are useful syntheses. Cambridge University Press & Assessment
• NIH / ODS and NCCIH summaries. These government-sourced fact sheets review clinical evidence and safety, noting evidence for stress/anxiety and recommending caution in certain populations. Office of Dietary Supplements

Direct PTSD-specific research (preclinical / animal):

• Alzoubi / Withania somnifera 2019 (Mol Biol Rep / Springer). Animal study using single-prolonged stress rat model of PTSD — oral root powder prevented PTSD-induced memory impairment (doses reported in mg/kg). This supports biological plausibility but is preclinical. SpringerLink

Safety / dosing trials

• Randomized placebo-controlled safety trials (e.g., 300 mg twice daily for 8 weeks in healthy adults) showed good short-term tolerability. Longer-term safety studies are ongoing/registered. ScienceDirect