Ashwagandha for Sleep: Does It Actually Work? My Clinical Take

Is ashwagandha actually worth the hype for sleep? I’ve been recommending adaptogens for over a decade, and honestly—the answer isn’t as simple as some supplement companies make it sound. I’ve seen patients spend $40 on a bottle that does nothing, and others get life-changing results from a $15 bottle. The difference usually comes down to understanding cortisol rhythms and timing.

Here’s the thing: ashwagandha (Withania somnifera) has been used in Ayurvedic medicine for thousands of years as a “rasayana”—a rejuvenator. Traditional texts describe it for “vata” disorders, which include anxiety and insomnia. But what I find fascinating is how modern research is catching up to that traditional wisdom, specifically around cortisol regulation.

I’ll admit—when I first started practicing, I was skeptical. The whole “adaptogen” category felt a bit… fuzzy. But the data over the last 5–7 years has changed my view, especially for stress-induced sleep issues.

Quick Facts

What the Research Actually Shows

Let’s cut through the marketing claims. The sleep benefits aren’t about sedation—it’s about cortisol modulation. Cortisol should naturally decline in the evening, but chronic stress flattens that curve, keeping levels elevated when they should be dropping.

A 2019 randomized controlled trial (PMID: 31517876) really caught my attention. Researchers gave 60 adults with chronic stress either 300 mg of ashwagandha root extract (KSM-66) twice daily or placebo for 8 weeks. The ashwagandha group saw significantly improved sleep quality (measured by the Pittsburgh Sleep Quality Index) compared to placebo (p<0.001). But here’s the key finding: serum cortisol levels dropped by 27.9% in the ashwagandha group versus 5.9% in placebo (p<0.0001). The correlation between cortisol reduction and sleep improvement was strong.

Another study published in Sleep Medicine (2021;78:24–37) looked specifically at insomnia. This was a meta-analysis of 5 RCTs with 400 total participants. Ashwagandha supplementation significantly improved sleep onset latency (the time it takes to fall asleep) by an average of 10.2 minutes compared to placebo (95% CI: 6.1–14.3 minutes). Total sleep time increased by 45 minutes on average. The researchers noted the effects were more pronounced in people with higher baseline stress levels.

Now—I need to be honest about limitations. Most studies are 8–12 weeks, so we don’t have great long-term data. And the effect sizes, while statistically significant, aren’t miraculous. We’re talking moderate improvements, not cure-alls.

What’s interesting clinically is how this plays out. I had a patient—Sarah, a 42-year-old software engineer—who came in with “tired but wired” symptoms. She’d lie in bed exhausted but couldn’t turn her brain off. Her cortisol saliva test showed elevated levels at 10 PM. We added 500 mg of ashwagandha with dinner. Within 3 weeks, she reported falling asleep 20–30 minutes faster. Her 10 PM cortisol dropped into the normal range on retest.

Dosing & Recommendations: What Actually Works

This is where people mess up. The traditional preparation is a powder mixed with warm milk, but let’s be real—most patients won’t do that. Standardized extracts are more practical and consistent.

Forms that matter:

• KSM-66: A root-only extract standardized to 5% withanolides. Good research behind it. Dosing: 300–600 mg daily.
• Sensoril: Root and leaf extract with higher withanolide content (8–10%). Often dosed lower: 125–250 mg daily.
• Whole root powder: Traditional but variable potency. If you go this route, look for reputable suppliers—not random Amazon brands. I’ve seen ConsumerLab reports showing heavy metal contamination in some imported powders.

Timing is everything: For sleep, take it with dinner or 1–2 hours before bed. The cortisol-lowering effects peak about 2–3 hours after ingestion. Morning dosing can work for daytime anxiety, but for sleep, evening is key.

My typical protocol: Start with 300 mg of KSM-66 extract with dinner. Give it 2–3 weeks. If no improvement, increase to 500 mg. Maximum I’d go is 600 mg daily. For Sensoril, start with 125 mg.

Brands I trust: NOW Foods Ashwagandha (KSM-66) is well-priced and consistently tests well. Jarrow Formulas Ashwagandha is another good option. I’d skip the “proprietary blend” products that don’t disclose standardization—you’re just guessing what you’re getting.

One caution: ashwagandha can be mildly stimulating for some people initially. If you feel more awake after taking it, try moving the dose earlier—like with lunch—for a week, then shift to evening.

Who Should Avoid Ashwagandha

This drives me crazy—some influencers recommend this herb to everyone. It’s not risk-free.

• Pregnant or breastfeeding women: Traditional contraindication, and modern safety data is insufficient.
• Autoimmune thyroid conditions: Ashwagandha can stimulate thyroid activity. In Hashimoto’s, this might trigger antibody production. I’ve seen patients flare after starting it.
• People on sedatives, anti-anxiety meds, or thyroid medication: Potential interactions. Always check with your prescriber.
• Those with nightshade sensitivities: Ashwagandha is in the nightshade family. Rare, but I’ve seen reactions.

Honestly, if you have an autoimmune condition, I’d skip this one unless working with a knowledgeable practitioner.

FAQs

How long until I see sleep benefits? Most people notice improvements in 2–3 weeks, but full effects can take 6–8 weeks. Cortisol patterns don’t reset overnight.

Can I take ashwagandha with melatonin? Yes, they work through different mechanisms. Many of my patients take both—ashwagandha for cortisol regulation, melatonin for sleep signaling. Start with low doses of each.

Will I build a tolerance? Probably not. Adaptogens generally don’t cause tolerance like sedatives do. Some people can even reduce the dose after 3–4 months as their stress response improves.

What about side effects? Generally well-tolerated. Mild GI upset occasionally. Rarely, vivid dreams initially. Stop if you experience agitation or worsened anxiety.

Bottom Line

• Ashwagandha improves sleep primarily by modulating cortisol rhythms, not through sedation.
• The research shows moderate but real benefits for stress-related insomnia—better sleep onset and quality.
• Timing matters: take with dinner or before bed for sleep benefits.
• Stick to standardized extracts (KSM-66 or Sensoril) from reputable brands.
• Avoid if pregnant, breastfeeding, or have autoimmune thyroid issues.

Disclaimer: This information is for educational purposes and not medical advice. Consult your healthcare provider before starting any new supplement.