Saffron for Anxiety: What the Evidence Shows

Saffron — the most expensive spice in the world — is now sold in capsules as a natural fix for anxiety and low mood.

The headline numbers look almost too good. But read past the abstract and the picture gets honest fast. The pooled trials show a large effect size for anxiety (g = 0.95), yet the same meta-analysis flags publication bias. The two best-designed trials in healthy adults missed their primary outcome. And a striking share of the positive studies were funded by the companies that sell the extract. Saffron is plausible and low-risk at a standardized ~30 mg/day, but the evidence is thinner and more conflicted than the marketing suggests.

Does saffron actually reduce anxiety?

On paper, the case is strong. A 2019 systematic review and meta-analysis in Nutrition Reviews (Marx et al.) pooled 23 studies and found saffron had a large positive effect size versus placebo for anxiety symptoms (g = 0.95, P < 0.006) — and an even larger one for depressive symptoms (g = 0.99, P < 0.001). If you stop reading there, saffron looks like a botanical Xanax.

The authors didn’t stop there. Their own conclusion is hedged: Egger’s regression test “found evidence of publication bias,” and they cited a “lack of regional diversity” — most trials came out of a handful of research groups in Iran, the world’s largest saffron producer. Their verdict was that saffron “could be an effective intervention,” but “further trials are required.” A large effect size built on a biased, geographically narrow literature is a promising signal, not a settled fact.

What happens when saffron is tested in healthy, stressed adults?

This is where the honest version diverges from the sales page. The two most rigorous recent trials in exactly the population buying these capsules — healthy adults with subclinical stress and low mood — both failed their primary outcome.

In a 2020 double-blind RCT (Jackson et al., Frontiers in Nutrition), 56 healthy adults took 30 mg of standardized saffron extract for eight weeks. There was no effect of treatment on the primary outcome (total mood disturbance on the Profile of Mood States). Only a secondary subscale — self-reported depressed mood — reached significance (p = 0.05). The study was funded by a saffron extract manufacturer.

The newest and one of the largest of its kind — a 2025 double-blind RCT (Amadieu et al., American Journal of Clinical Nutrition) — gave 51 healthy adults with subclinical symptoms 30 mg of saffron daily for six weeks. Again, no significant difference on the primary outcome: both the saffron and placebo groups improved similarly, a textbook placebo response. Saffron edged ahead only on a secondary mental-health quality-of-life score (P = 0.04), with no effect on cortisol or inflammatory markers — the mechanisms it’s supposed to work through. The pattern is familiar from the supplement literature: people feel a bit better, but so does the placebo group, and the primary endpoint won’t confirm a saffron-specific effect.

What’s the catch — who funds these studies?

The funding is the catch, and it’s not a minor footnote. McGill University’s Office for Science and Society reviewed the saffron-mood literature and found it built on “very small clinical trials,” often comparing two groups of roughly 20 participants for six to eight weeks. Many were funded by saffron manufacturers. In one telling case McGill flagged, an industry-funded trial “came up negative until the data was tortured to confess.”

This matters more for saffron than for most supplements because the extract is expensive to produce and the makers have a direct commercial stake in the outcome. When the independent, adequately-powered trials keep landing on null primary endpoints while the industry-adjacent ones report wins, the reasonable read is: expect the true effect to be smaller than the g = 0.95 headline.

What dose, which form, and is it safe?

If you try it anyway, the trials point to a standardized saffron extract at roughly 28–30 mg per day — the dose used in the Jackson and Amadieu studies, and matched by an earlier trial (Kell et al., 2017) in which 28 mg beat placebo for low mood but 22 mg did not, a hint that the effect, if real, is dose-sensitive. Look for a standardized extract (affron is the most-studied), not raw spice or vague “saffron powder.”

Safety is reassuring at these doses: culinary and supplement amounts are well tolerated, with toxicity concerns only at daily doses of about 5 grams or higher — orders of magnitude above any capsule (and prohibitively expensive). The bigger real-world risk is adulteration, since the spice’s cost invites cheaper substitutes.

How does saffron compare to the other options?

Against the supplements with cleaner data, saffron sits mid-pack. Ashwagandha has stronger cortisol-lowering trial evidence for stress — though it carries its own liver-injury caveat. Magnesium is cheaper and better-studied for sleep, if modest. And L-theanine has faster, calmer-focus data for acute stress. None of these is a cure, and saffron’s honest ranking is “plausible, pricey, and compromised by who paid for the research.”

The takeaway

Saffron isn’t snake oil — there’s a real, repeatable signal for mood, and it’s safe at studied doses. But the effect is inflated by publication bias and industry funding, and the two best independent trials couldn’t beat placebo on their primary endpoint. Treat a standardized ~30 mg/day extract as a low-stakes experiment, not a treatment. For the system this sits inside — actually regulating a keyed-up nervous system — see our anxiety regulation and sleep restoration work.