Ashwagandha and rhodiola: what the evidence says about taking them together

Ashwagandha and rhodiola are both called adaptogens and sold for stress and fatigue, but no trial has tested them together. Each has its own placebo-controlled trial: rhodiola's improved burnout-scale scores and attention measures in adults with diagnosed stress-related fatigue, and ashwagandha's lowered stress-scale scores and cortisol in adults with chronic stress — at doses that don't overlap with each other.

What the evidence doesn't support

It doesn't support a claim that ashwagandha and rhodiola work better together than either alone — that combination has never been tested. It doesn't support "adaptogen" as a mechanism these trials confirmed; it's a traditional term with no regulatory definition, not a lab-verified category. And it doesn't support carrying either ingredient's dose findings over to a combined product, since neither trial included the other ingredient.

What the trials found

A 2009 randomized, double-blind, placebo-controlled trial gave adults meeting diagnostic criteria for stress-related fatigue either four tablets a day of a standardized rhodiola extract (576 mg/day) or placebo, for 28 days. Both groups improved on several measures over time — a placebo effect — but comparing the groups directly, rhodiola outperformed placebo on the burnout scale and several attention-test measures, and was linked to a bigger drop in cortisol response to waking stress.

Ashwagandha's comparable trial used a different extract and a different, non-diagnosed population. A 2012 randomized, double-blind, placebo-controlled study gave 64 adults with a history of chronic stress 600 mg/day of a high-concentration root extract for 60 days; the treatment group had lower stress-scale scores and lower cortisol than placebo by day 60. A 2024 meta-analysis of nine trials, 558 people, found similar results pooled across a wider set of doses.

Neither rhodiola's trial nor ashwagandha's trials tested the other ingredient, and no study has measured what changes, if anything, when the two are taken together. The doses used — 576 mg/day of a standardized rhodiola extract, 600 mg/day of a concentrated ashwagandha extract — are each specific to their own single-ingredient trial, not a combined product.

Ingredient	Best evidence	Population	Dose in that trial
Rhodiola	Better burnout-scale and attention scores, bigger cortisol drop vs placebo (n=60)	Adults diagnosed with stress-related fatigue	576 mg/day extract, 28 days
Ashwagandha	Lower stress-scale scores and cortisol vs placebo (n=64)	Adults with chronic stress	600 mg/day extract, 60 days
Both together	No trial exists	—	—

Questions people ask

Can you take rhodiola and ashwagandha together?

There's no trial of the combination, so there's no research describing an added effect from taking them together. Each has its own separate safety profile; checking with a doctor or pharmacist before combining any two supplements is reasonable, particularly if you take other medication.

Is ashwagandha or rhodiola better for stress?

This page doesn't rank one over the other. As a description of the evidence: rhodiola's trial recruited people already diagnosed with stress-related fatigue and used a single standardized extract dose; ashwagandha's trials used a different concentrated extract in people with self-reported chronic stress, not a formal diagnosis. The two aren't directly comparable studies.

When to talk to a doctor

Fatigue or stress severe enough to affect daily functioning is worth discussing with a doctor, especially if it meets criteria for a diagnosed condition the way the rhodiola trial's participants did. Neither rhodiola nor ashwagandha is a treatment for a diagnosed fatigue or stress condition, and nothing in the evidence above supports using either, alone or combined, as a substitute for medical evaluation.

Related reading: what is ashwagandha, ashwagandha dosage, and ashwagandha interactions.