Can You Take Ashwagandha Every Day? The 2026 Long-Term Safety Answer
For years the answer was “probably yes, but the long-term data is thin.” A 2025 12-month prospective trial in 191 adults closes that gap. Here’s what it found.
Quick answer: Yes, for most healthy adults, KSM-66® ashwagandha at 600mg/day daily for 12 months is well-tolerated based on the largest published prospective safety study to date. The 2025 12-month study in 191 adults found 9.4% mild adverse events, no serious adverse events, and stable lipid/glucose markers. The trials don’t cycle. Optibio® Ashwagandha KSM-66® uses the trial dose.†
For most of ashwagandha’s peer-reviewed history the longest controlled trials ran 8 to 12 weeks. That left a real gap: efficacy was clear but long-term safety data was thin. People who wanted to use ashwagandha as a multi-year tool were extrapolating beyond the data.
That gap closed in 2025 with a 12-month prospective trial designed specifically to answer this question.
The 2025 12-month KSM-66® safety study
- Subjects: 191 healthy adults
- Protocol: KSM-66®-grade root extract daily for 12 months
- Monitoring: Monthly clinical assessments + laboratory panels at baseline, 6 months, 12 months
- Adverse events: 9.4% reported mild adverse events; 0% serious adverse events
- Liver/kidney function: No significant changes
- Lipids and glucose: Stable across the study
- Cortisol: Sustained reduction across 12 months
- Testosterone: Significant increase (sustained, not a 90-day spike)
- Subjective improvement: 68.7% reported overall clinical benefit, with the largest gains in adults 50+
Coverage: NutraIngredients (January 2026).
This is the longest-running prospective KSM-66®-grade safety study in the literature. It doesn’t prove safety beyond 12 months, but it’s a substantial extension of the evidence floor.
Should you cycle ashwagandha?
The published trials don’t cycle. The 12-month safety study didn’t cycle. The Choudhary 2017 cognitive trial, the Wankhede 2015 strength trial, the Langade 2019 sleep trial, none cycled. Subjects took it daily for the entire study duration.
Some athletes and clinicians still recommend 8 weeks on / 2 weeks off as a precaution, partly out of habit from older supplement-cycling guidance, partly because long-term data didn’t exist until recently. With the 2025 12-month data, that precautionary cycling is now optional rather than necessary.
If you cycle, that’s fine. If you don’t, the 12-month evidence supports continuous dosing.
When to NOT take ashwagandha daily
- Pregnancy/breastfeeding, insufficient safety data; avoid.
- Hyperthyroidism, ashwagandha may modestly increase thyroid hormone; can be problematic in this condition.
- Active autoimmune disease, theoretical concern about immune modulation; consult your physician.
- On thyroid medication (levothyroxine, etc.), possible to require dose adjustment; coordinate with your endocrinologist.
- On sedatives, anxiolytics, or immunosuppressants, potential additive effects or interactions; talk to your prescriber first.
- Known nightshade allergy, ashwagandha is in the Solanaceae family.
Frequently asked questions
Is ashwagandha safe to take every day forever?
Best evidence today supports daily use for at least 12 months in healthy adults. Beyond 12 months, the data thins out. For most people the practical answer is yes, with annual check-ins on labs you’d run anyway (CBC, metabolic panel, lipids, thyroid).
Will daily ashwagandha stop working over time?
Tolerance has not been documented in the trials. The 2025 12-month study showed sustained, not declining, cortisol reduction and clinical benefit through month 12.
Should I take a break from ashwagandha?
The trials don’t require it. If you prefer to cycle 8 on / 2 off as a precaution, that’s reasonable but not necessary based on the latest evidence.
Are there side effects from daily ashwagandha?
The 2025 study reported 9.4% mild adverse events, mostly GI (nausea, loose stools), drowsiness, or mild headache, resolving with continued use or dose timing change. No serious adverse events.
Can I take ashwagandha forever or should I stop after a year?
The 12-month data supports continued use. Beyond 12 months is “probably fine” based on traditional use plus extrapolation, but not directly evidenced. Most clinicians treat it as ongoing baseline support like a multivitamin or omega-3.
The bottom line
Yes, for most healthy adults, KSM-66® at 600mg/day daily is well-tolerated for at least 12 months based on the largest published prospective safety study. Cycling is optional. Stick to a clinically dosed, third-party-tested product. Optibio® Ashwagandha KSM-66® matches the trial dose exactly.†
Related: complete dosage guide, best time to take ashwagandha, our science page.
Shop Optibio Ashwagandha KSM-66® →
†These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. Consult your healthcare provider before starting any supplement, especially if you are pregnant, breastfeeding, or taking medications.