Last updated: October 2026
Reishi and ashwagandha are very different: reishi (Ganoderma lucidum) is a mushroom, and ashwagandha (Withania somnifera) is a herb root. Ashwagandha has more human research, mainly on stress and cortisol. Reishi has been studied mostly for fatigue and wellbeing, in very few trials. For both, the evidence is small, and neither is a treatment for any condition.
Reishi vs ashwagandha at a glance
| Reishi | Ashwagandha | Notes | |
|---|---|---|---|
| What it is | A mushroom | A herb root | Reishi is a fungus |
| Main research | Fatigue, wellbeing | Stress, cortisol | Neither is a treatment |
| Human evidence | Very few trials | Small trials and meta-analyses | Most trials are short |
| Usual time | Evening | Any time, with food | Routine matters most |
| Main cautions | Blood thinners, liver | Thyroid, liver, autoimmune | On medicines? Ask a pharmacist |
| UK status | Sold as a food supplement | Legal; FSA review ongoing | No UK limit set yet |
What the research shows
Reishi
In a controlled trial of 132 adults with neurasthenia, a condition with long-term fatigue, irritability and poor sleep, a reishi extract over 8 weeks improved fatigue and wellbeing more than placebo. Human sleep trials are lacking, so it’s best seen as a gentle evening ritual rather than a proven treatment. See reishi mushroom, reishi for sleep and mushrooms for anxiety.
Ashwagandha
A 2024 meta-analysis of 9 trials (558 people) found ashwagandha reduced perceived stress, anxiety and cortisol. A 2025 meta-analysis of 488 people confirmed lower cortisol but found no clear effect on perceived stress. See what ashwagandha does, ashwagandha for anxiety and ashwagandha and sleep.
Which should you choose?
| If you want… | Consider |
|---|---|
| The most researched option for stress | Ashwagandha, if it’s safe for you |
| A gentle evening ritual | Reishi, often as a warm drink |
| To avoid thyroid or liver concerns | Reishi (check if you take blood thinners) |
| Something for daytime | Ashwagandha, or neither: see adaptogens for energy |
Our Reishi Mushroom Adaptogenic Complex is a reishi hot chocolate with reishi mushroom extract, organic cacao and maca; it contains a little natural caffeine. Flow CBD Oil combines broad spectrum CBD (0% THC) with ashwagandha and maca. See the best mushroom supplements in the UK.
Our Magnesium Glycinate Sleep Complex has no ashwagandha or reishi. Magnesium contributes to a reduction of tiredness and fatigue and to normal psychological function. All our products are for adults (18+) only.
The FSA’s 10mg a day figure is precautionary advice rather than a legal limit, set while longer-term safety research continues. At Evopure we think it is a very cautious figure, and many adults use more. If you go above it, increase slowly, and check with your GP or pharmacist first if you take any medication.
Can you take reishi and ashwagandha together?
Yes, many people take ashwagandha and reishi together, often ashwagandha by day and reishi in the evening. But we found no published trial of the combination, so its benefits are untested. Both can have mild effects on blood pressure and blood sugar, and ashwagandha can make some people drowsy, so check with a pharmacist if you take medicines for those, or sedatives.
- Start one at a time: give each a couple of weeks so you can tell how it affects you.
- Check blends: read the full ingredients list.
- Adding CBD? See CBD and ashwagandha together.
Ashwagandha, reishi and griffonia blends
Some blends add griffonia to ashwagandha and reishi. Griffonia simplicifolia is an African plant, and its seeds are the main natural source of 5-HTP, which the body turns into serotonin. 5-HTP can interact with antidepressants and other medicines that raise serotonin, which risks a serious reaction called serotonin syndrome. If you take any of these, ask your GP or pharmacist first. Our products contain no griffonia or 5-HTP. See our 5-HTP guide.
When to take reishi and ashwagandha
- Ashwagandha: trials didn’t compare times of day, so take it when you’ll remember, with food. Sleep trials gave it in the evening. See when to take ashwagandha and how much ashwagandha per day.
- Reishi: often taken in the evening. A reishi cacao drink contains a little natural caffeine, so if you’re sensitive, have it earlier.
- How long: ashwagandha may be safe for up to 3 months; longer-term safety isn’t known.
Safety and UK status
- Ashwagandha in the UK: it’s legal as a food supplement, but the FSA is reviewing its safety. Its June 2026 summary of a call for evidence says the Committee on Toxicity (COT) will assess it, the risk assessment will be published, and all four UK nations will review it. The COT discussed a third draft statement in private on 8 September 2026; no UK limit or warning has been set yet. See the UK safety review.
- Ashwagandha and the liver: liver injury is rare but reported. Stop and see your GP if you notice yellowing skin or eyes, or dark urine. See ashwagandha side effects.
- Thyroid: ashwagandha changed thyroid hormone levels in an 8-week trial of 50 adults with a mildly underactive thyroid. Avoid it with a thyroid condition, thyroid medicine or autoimmune disease unless your doctor agrees.
- Reishi and the liver: usually well tolerated, though it can upset the stomach. Case reports link reishi powder to liver injury, including a fatal case in 2007 and a 2023 case, alongside alcohol, that fully resolved.
- Reishi and blood thinners: reishi may increase the risk of bleeding. Avoid it with warfarin or other blood thinners, or before surgery, unless your doctor agrees.
- Pregnancy: avoid ashwagandha when pregnant or breastfeeding. We don’t recommend our products during pregnancy or breastfeeding.
Related guides
- Ashwagandha vs magnesium, ashwagandha vs rhodiola and holy basil (tulsi).
- Reishi vs cordyceps vs lion’s mane and our guide to adaptogenic mushrooms.
- How much maca root per day, an ingredient in both our blends.
- Routine first: how to lower cortisol naturally.
- For the different ways to take reishi, see reishi powder vs extract vs tincture.
- If you choose ashwagandha, give it time: how long ashwagandha takes to work explains what to expect.
- If you choose reishi, the classic way to take it is as reishi tea.
FAQs
What is the difference between reishi and ashwagandha?
Reishi is a mushroom traditionally used for calm and sleep. Ashwagandha is a herb root studied mainly for stress and cortisol.
Is reishi or ashwagandha better for anxiety?
Ashwagandha has more human research for stress and anxiety. Reishi is traditionally used for evening calm, with less evidence. Neither is a treatment for anxiety.
Is reishi or ashwagandha better for sleep?
Both are used in evening routines. Neither has strong human sleep evidence; good sleep habits matter more.
Can I take reishi and ashwagandha together?
Many people do, but the combination hasn’t been tested in trials. Start one at a time, and check with a pharmacist if you take medicines.
What are the benefits of ashwagandha and reishi together?
No published trial has tested them together, so there are no proven benefits of the combination. Each has its own small body of research.
Is ashwagandha safe in the UK?
It’s legal as a food supplement, but the FSA and its Committee on Toxicity are reviewing its safety. Avoid it with thyroid or liver conditions, autoimmune disease or in pregnancy.
Sources
- Tang W et al (2005). A randomized, double-blind and placebo-controlled study of a Ganoderma lucidum polysaccharide extract in neurasthenia. Journal of Medicinal Food.
- Arumugam V et al (2024). Effects of ashwagandha on stress and anxiety: a systematic review and meta-analysis. Explore.
- Albalawi AA (2025). Dual impact of ashwagandha: significant cortisol reduction but no effects on perceived stress. Nutrition and Health.
- Sharma AK et al (2018). Efficacy and safety of ashwagandha root extract in subclinical hypothyroid patients. Journal of Alternative and Complementary Medicine.
- Wanmuang H et al (2007). Fatal fulminant hepatitis associated with Ganoderma lucidum (Lingzhi) mushroom powder. Journal of the Medical Association of Thailand.
- Guedikian R et al (2023). Ganoderma lingzhi (reishi mushroom)-induced acute liver injury in the setting of alcohol use. Cureus.
- Maffei ME (2020). 5-Hydroxytryptophan (5-HTP): natural occurrence, analysis, biosynthesis, biotechnology, physiology and toxicology. International Journal of Molecular Sciences.
- FSA (June 2026). Summary of responses to call for evidence on ashwagandha.
- COT. Draft minutes, 8 September 2026 meeting.
- NCCIH. Ashwagandha.
- Memorial Sloan Kettering. Reishi mushroom.
This guide is general information, not medical advice. Evopure makes the Reishi Mushroom Adaptogenic Complex and Flow CBD Oil.
