Rhodiola rosea: the evidence, and how it compares with ashwagandha
What rhodiola rosea is, what its trials show, who should avoid it, and how it compares with ashwagandha.
- Written by
- Mustafa K.
- Last updated
- Reading time
- 7 min read
Overview
Rhodiola rosea, or roseroot, is a herb registered in the UK as a traditional herbal medicine for stress symptoms such as fatigue and exhaustion. Its trials are small and their results disagree. Ashwagandha has more consistent results for cortisol and sleep. No trial has compared the two head to head.
Key points
- What it is: the root of roseroot, a traditional herbal medicine in the UK.
- Evidence: small trials on tiredness disagree; small endurance gains in athletes.
- Vs ashwagandha: ashwagandha has more consistent results for cortisol and sleep.
- Together: one 2-week trial has tested them as a pair.
- Avoid it: if you're under 18, pregnant or breastfeeding.
What is rhodiola rosea?
Rhodiola rosea, also called roseroot or Arctic root, is a plant whose root is dried and made into an extract [1]. It has been used as a herbal medicine in Europe since 1987, when it was first licensed in Sweden [1].
In the UK, rhodiola tablets and capsules can be registered as traditional herbal medicines. Two such registrations cover several high-street brands. Their approved use is "for the temporary relief of symptoms associated with stress such as fatigue, exhaustion and mild anxiety, based on traditional use only" [2].
A traditional herbal registration rests on at least 30 years of use, 15 of them in Europe, rather than on proof from trials [2].
What is rhodiola rosea good for?
Mainly stress-related tiredness, though the trials disagree. Most were small, short and run in young adults such as students, cadets and athletes [3].
| Study | Who | Result | Evidence |
|---|---|---|---|
| Review of 11 trials, 2012 [3] | 446 people, mostly young and healthy | 3 of 5 mental fatigue trials and 2 of 6 physical fatigue trials were positive. All were at high or unclear risk of bias | Mixed |
| Olsson 2009 [4] | 60 adults with stress-related fatigue | 576 mg a day for 28 days. Burnout scores improved slightly more than on a placebo | Early |
| Punja 2014 [5] | 48 student nurses on shift work | 364 mg a day for 6 weeks. Fatigue was worse than on a placebo | Early |
| Review of 26 trials, 2025 [6] | 668 active adults, average age 22 | Small gains in endurance, such as VO2 max | Moderate |
When the EU's herbal medicines committee reviewed rhodiola in 2024, it found the trials "exhibit considerable deficiencies in their quality" [1]. That's why rhodiola is approved on traditional use, not on trial results. Our page of rhodiola studies lists every trial in people.
Rhodiola vs ashwagandha: how they compare
Both are called adaptogens, plants taken to help the body handle stress. We found no trial comparing them head to head, but their research looks quite different.
| Rhodiola rosea | Ashwagandha | |
|---|---|---|
| Part used | Root of roseroot [1] | Root of Withania somnifera |
| Main research | Tiredness, attention and exercise endurance [3, 6] | Cortisol, felt stress and sleep [7, 8] |
| Usual daily amount | 144 to 400 mg of extract [1] | 250 to 600 mg of root extract in trials [7] |
| Trial length | A single dose to 6 weeks [3, 5] | Often 8 weeks or more [8] |
| Evidence | Tiredness Mixed Endurance Moderate |
Cortisol Moderate Sleep Moderate Felt stress Mixed |
| UK status | Traditional herbal medicine [2] | Food supplement; no herbal registration [2] |
Across 7 trials, ashwagandha lowered cortisol, the main stress hormone, by about 1.16 µg/dL more than a placebo. It didn't clearly change how stressed people said they felt [7]. Across 5 trials with 400 people, it improved sleep, more so at 600 mg a day or more and after 8 weeks [8].
Which is better for stress?
It depends on what you want from it. Rhodiola's trials looked mostly at tiredness and short-term mental performance, often after a single dose or a few weeks [3]. Ashwagandha's looked at stress hormones and sleep over about 8 weeks, with more consistent results [7, 8].
If calm and better rest matter most to you, ashwagandha has the stronger research. Read our complete guide to ashwagandha for its dose, timing and safety advice.
Can you take rhodiola and ashwagandha together?
Many supplements combine them, but only one placebo-controlled trial has tested the pair. In 2026, active adults took 300 mg of rhodiola with 600 mg of ashwagandha each morning for 2 weeks. Their perceived stress fell slightly more than on a placebo, and 2 of 29 stopped with possible side effects: diarrhoea, and dizziness with muscle weakness [9].
That's one short trial, so it can't say which herb did what. For other pairings, see our guide to nootropic stacks.
Rhodiola side effects and cautions
Reported side effects are headache, nausea, stomach pain, diarrhoea, rash and itching. How often they happen isn't known [1].
Where Nooroots fits
Nooroots Ashwagandha + Lion's Mane doesn't contain rhodiola. It pairs 120 mg of KSM-66 ashwagandha with 500 mg of lion's mane extract in two caffeine-free capsules a day, made for calm focus and calm resilience on demanding days.
Read more about the other half of the formula in our complete guide to lion's mane.
Frequently asked questions
What does rhodiola do?
In the UK it's registered as a traditional herbal medicine for the temporary relief of stress symptoms such as fatigue and exhaustion [2]. Trials of it for tiredness disagree [3].
What is rhodiola extract?
A dried extract of the root, made with alcohol. Registered UK products contain 153 mg or 200 mg of extract in each tablet or capsule [2].
How much rhodiola rosea should I take?
The EU's traditional dose for adults is 144 to 200 mg of extract once or twice a day, up to 400 mg a day [1]. Follow the label of the product you buy.
How long does rhodiola take to work?
Some trials tested people about an hour after a single dose. Most lasted no more than 4 weeks [3].
Is rhodiola better than ashwagandha for stress?
No trial has compared them. Ashwagandha has more consistent results for cortisol and sleep [7, 8], while rhodiola's trials, mostly on tiredness, disagree [3].
References
Every study here is listed so you can read it yourself. This guide is for general information and doesn't replace advice from your GP or pharmacist. We review it when new research is published.
- European Medicines Agency, Committee on Herbal Medicinal Products (2024). European Union herbal monograph on Rhodiola rosea L., rhizoma et radix, Revision 1 (EMA/HMPC/24177/2023), and its assessment report (EMA/HMPC/24186/2023). ema.europa.eu/en/medicines/herbal/rhodiolae-roseae-rhizoma-et-radix
- Medicines and Healthcare products Regulatory Agency. Herbal medicines granted a traditional herbal registration (THR). Updated 28 October 2025. gov.uk/government/publications/herbal-medicines-granted-a-traditional-herbal-registration-thr. And: Apply for a traditional herbal registration (THR). Updated 5 January 2024. gov.uk/guidance/apply-for-a-traditional-herbal-registration-thr
- Ishaque S et al. (2012). Rhodiola rosea for physical and mental fatigue: a systematic review. BMC Complementary and Alternative Medicine 12: 70. PMID 22643043
- Olsson EM et al. (2009). A randomised, double-blind, placebo-controlled, parallel-group study of the standardised extract SHR-5 of the roots of Rhodiola rosea in the treatment of subjects with stress-related fatigue. Planta Medica 75(2): 105–112. PMID 19016404
- Punja S et al. (2014). Rhodiola rosea for mental and physical fatigue in nursing students: a randomized controlled trial. PLoS One 9(9): e108416. PMID 25268730
- Wang X et al. (2025). The effect of Rhodiola rosea supplementation on endurance performance and related biomarkers: a systematic review and meta-analysis. Frontiers in Nutrition 12: 1645346. PMID 41080184
- Albalawi AA (2025). Dual impact of Ashwagandha: significant cortisol reduction but no effects on perceived stress. A systematic review and meta-analysis. Nutrition and Health 31(4): 1395–1408. PMID 40746175
- Cheah KL et al. (2021). Effect of Ashwagandha (Withania somnifera) extract on sleep: a systematic review and meta-analysis. PLoS One 16(9): e0257843. PMID 34559859
- Mastrofini GF et al. (2026). Modulating stress and sleep through a multi-compound dietary supplement: a randomized, double-blind, placebo-controlled trial. Journal of the International Society of Sports Nutrition 23(1): 2740227. PMID 42829807
- Thu OK et al. (2016). Effect of commercial Rhodiola rosea on CYP enzyme activity in humans. European Journal of Clinical Pharmacology 72(3): 295–300. PMID 26613955
