Does ashwagandha actually lower cortisol?

What the cortisol claim actually means

Cortisol is the hormone your adrenal glands release when your brain flags a threat, real or imagined. It spikes in the morning to get you moving and should taper off through the day. Chronic stress keeps it elevated, which is linked to poor sleep, weight gain around the middle, and a wired, foggy feeling that never fully resolves. Ashwagandha, a root used in Ayurvedic medicine for centuries, is now marketed as a way to bring that curve back down. The question is whether a daily capsule actually does that, or whether it is riding the adaptogen trend on vibes alone. Unlike a lot of supplement claims, this one has actually been tested with blood and saliva draws, not just surveys, which makes it worth a closer look.

The clearest single trial: a 23% drop

The best known controlled trial here comes from Adrian Lopresti and colleagues at Murdoch University, published in the journal Medicine in 2019. Sixty adults with a recent history of stress took either 240 mg of a standardized ashwagandha extract or a placebo for 60 days. The ashwagandha group's morning cortisol fell by 23%. The placebo group's rose slightly, by 0.5%. The difference was statistically significant, and nobody dropped out from side effects. That is a real, measurable hormonal change, not a number invented for a supplement label. The same trial also tracked the Perceived Stress Scale and reported meaningful improvements there too, which is part of why this particular study gets cited so often.

What happens when you pool the trials

One study is not proof of a pattern, so it matters that pooled data tells a similar story. A 2025 systematic review and meta-analysis in BJPsych Open combined 15 randomized controlled trials covering 873 adults. At eight weeks, cortisol had dropped significantly across the pooled trials, alongside meaningful improvements on anxiety and perceived stress scales. The same review found no significant improvement in quality of life scores, a detail marketing pages tend to leave out. Lower cortisol and better anxiety scores did not reliably translate into people rating their day to day life as improved. That combination, a solid biomarker signal next to a shakier quality of life signal, is the honest state of the evidence right now.

Lower cortisol does not always mean you feel calmer

This is the gap worth sitting with. Other analyses of the same body of trials have found a similar split: cortisol drops on lab tests, but perceived stress, the number someone gives when you ask how stressed they feel, moves less consistently. That is not a contradiction so much as a reminder that a blood or saliva marker and a subjective feeling are two different outcomes, and a supplement can move one without moving the other. If your main goal is a lower reading on a cortisol panel, the evidence is decent. If your goal is to feel noticeably less frazzled, the evidence is thinner and more mixed. People dealing with chronic, low grade work stress seem to be the group most trials actually studied, so the evidence says less about acute panic or diagnosed anxiety disorders.

Dose, cost and safety

Trials showing benefit have generally used 240 mg to 600 mg per day of a standardized root extract, taken for four to twelve weeks. A month's supply of a reputable, standardized extract typically costs between fifteen and thirty dollars, which is cheap enough that the financial downside of trying it for a couple of months is small. Yufang Lin, MD, an integrative medicine specialist at Cleveland Clinic, describes ashwagandha as working like a classic adaptogen: "Less cortisol can mean you feel less stressed mentally, and it can lessen the physical effects of stress." Cleveland Clinic's guidance caps typical dosing at around 500 mg twice daily and notes it is generally well tolerated for three to six months, with drowsiness and gastrointestinal upset as the most common complaints. It also flags real caution points: ashwagandha can affect liver function and thyroid activity, and it is not recommended during pregnancy. None of the trials behind the cortisol numbers ran much past sixteen weeks, so long term safety data simply does not exist yet, and anyone on thyroid medication, sedatives, or immunosuppressants should check with a clinician first, as we've covered before.

Our take

Ashwagandha's cortisol effect is one of the better supported claims in the supplement aisle: multiple controlled trials and a 2025 meta-analysis of 873 adults show a real, statistically significant drop. What is not settled is whether that biochemical change reliably makes people feel calmer day to day, and long term safety data does not exist yet. Treat it as a reasonable short-term experiment worth a two to three month trial, paired with sleep and workload changes, not a standalone cure for stress.

This is general information, not medical advice. Talk to a clinician before changing anything, especially if you are pregnant, nursing, or managing a condition.