What is Rhodiola rosea? A plain-English guide

Rhodiola rosea is a plant that grows in cold places and high in the mountains of Europe, Asia and North America [10].

Supplements and herbal medicines use its dried root and rhizome, which is a root-like stem that grows underground [9]. Its other names include roseroot, king's-crown and hong jing tian [9]. The European Medicines Agency (EMA) calls it Arctic root [8].

Researchers have studied rhodiola for what one review calls its "purported adaptogenic properties" [1].

Today, rhodiola is promoted for sports performance, mood, thinking, energy and lower stress [10].

A US health agency, NCCIH, says there isn't enough reliable evidence to tell if rhodiola is useful for any health purpose [10].

Does rhodiola help with mental fatigue?

Evidence grade for mental fatigue: C, limited. Why this grade

A 2012 review looked at 11 controlled trials of rhodiola for tiredness of the body or mind [1]. Of the five randomized controlled trials on mental fatigue, three reported a benefit [1].

In a randomized controlled trial, people are put into groups by chance. One group often gets a placebo, which is a dummy pill with nothing active in it.

The same review found that every study it included had a high risk of bias or reporting flaws [1]. That means the way each study was run or written up made it hard to judge [1]. The review called the research "contradictory" [1]. A 2011 review noted that single studies had not been independently repeated [2].

A later registered trial randomly gave 48 nursing students on shift work rhodiola or a look-alike placebo for 42 days. Neither students nor researchers knew who got which [3]. Fatigue got worse with rhodiola than with the placebo, though the authors say the result should be read with caution [3]. The Government of Alberta funded this trial [3].

Does rhodiola lower stress?

Evidence grade for perceived stress: C, limited. Why this grade

As of November 11, 2026, we found no placebo-controlled trial of rhodiola alone on self-rated stress in healthy adults (PubMed and Europe PMC search).

In a trial funded by the company Dr Willmar Schwabe GmbH & Co. KG, 80 mildly anxious adults took rhodiola or nothing for 14 days [4]. The rhodiola group reported less stress than the untreated group, but the trial found no relevant difference in thinking test scores [4]. With no placebo group, the authors say they cannot tell if rhodiola caused the change [4].

Does rhodiola help with endurance?

Evidence grade for endurance performance: B, moderate. Why this grade

A meta-analysis is a study that pools the results of many trials to get one overall answer.

A 2025 meta-analysis pooled 26 randomized trials in 668 healthy people with an average age of 22 [5]. Compared with a placebo or control, rhodiola gave small gains on three endurance measures [5]. But the trials differed a lot from each other, so the authors say the results need cautious reading [5].

A 2026 meta-analysis of 9 randomized trials in 424 healthy adults looked at oxygen use [6]. It found no clear effect on the most oxygen the body can use during hard exercise [6]. It pooled several kinds of Rhodiola plants, not just Rhodiola rosea [6]. Its authors link the uncertain results to differences in study design, size, dose and length [6].

To see what each grade means, read how we grade evidence.

Table: Doses used in studies (not a recommendation)

These are amounts used in research, not advice for any reader. Talk to a clinician before using rhodiola.

A 2011 review of 11 placebo-controlled trials found only a few mild side effects [2]. A 2025 meta-analysis of 26 exercise trials found none reported, but its authors say underreporting cannot be ruled out [5].

EMA lists headache, nausea, stomach pain, diarrhea, skin rash and itching as possible side effects [8]. It says how often they happen is not known [8]. Health Canada's monograph requires the label statement "Stop use if you experience irritability or insomnia" [9].

EMA notes that some standard lab tests, such as tests for harm to reproduction or to genes, are not available [8].

Rhodiola may affect how the body handles some medicines [7]. In 13 healthy volunteers, 14 days of a rhodiola product lowered a marker of an enzyme called CYP2C9 by 21% [7]. An enzyme is a body protein that speeds up a chemical change; this one helps break down certain medicines [7]. It had no clear effect on the other enzymes tested [7]. The authors call the effect modest [7]. But they say it might matter for medicines with a narrow safe range, such as warfarin or phenytoin [7].

EMA's monograph, by contrast, says no clinically relevant interactions have been seen [8]. If you take any of these medicines, talk to your doctor or pharmacist before combining them with rhodiola.

• Pregnancy and breastfeeding: EMA does not recommend use because there is not enough data [8]. Health Canada's monograph says to ask a health care practitioner first [9]. As of November 11, 2026, we found no human studies of rhodiola in pregnancy or breastfeeding (PubMed and Europe PMC search).
• Children and teens: EMA does not recommend use under age 18 [8]. Health Canada's monograph covers adults 18 and older [9].
• People with bipolar disorder: Health Canada's monograph says "Do not use if you have bipolar disorder or bipolar spectrum disorder" [9].
• People who take medicines: Health Canada's monograph tells people taking antidepressants, hormone replacement therapy or birth control to ask a practitioner first [9]. The CYP2C9 study's authors say it might matter for warfarin or phenytoin [7].
• People allergic to the extract: EMA lists this as a reason not to use it [8].