Adaptogens: How Plants May Help With Stress

What Are Adaptogens?

The term “adaptogen” was coined in 1947 by Soviet pharmacologist Nikolai Lazarev and later scientifically defined by Israel Brekhman. According to Brekhman, an adaptogen must meet three criteria:

1. Non-specific action: It increases resistance to various stressors (physical, chemical, biological).
2. Normalising effect: It has a balancing effect on the organism, regardless of the direction of deviation.
3. No side effects: In normal dosages, it causes no significant side effects and does not negatively affect normal body functions.

This definition dates back to the 1960s. Modern research has refined it, but the core principles remain relevant.

How Do Adaptogens Affect the Stress Axis?

The central mechanism involves the HPA axis (hypothalamic-pituitary-adrenal axis). This is the body’s primary stress response system. Under stress, the hypothalamus releases CRH, which stimulates the pituitary gland to produce ACTH, which in turn prompts the adrenal glands to release cortisol.

Panossian and Wikman (2010) described in their comprehensive review that adaptogens may influence several molecular signalling pathways. These include heat shock proteins (Hsp70), the cortisol feedback loop, and nitric oxide. The authors suggest that adaptogens may modulate the stress response without fully suppressing it. The body should still react to stress, but more efficiently and with less collateral damage.

Scientifically Studied Adaptogens

Ashwagandha (Withania somnifera)

Ashwagandha is one of the most extensively studied adaptogens. A systematic review by Bonilla et al. (2021) summarised the evidence: In several randomised controlled trials, ashwagandha extract (300-600 mg/day) was associated with reduced cortisol levels and subjective stress perception. The effects were statistically significant but moderate. This is not a dramatic effect but rather a measurable level of support.

Rhodiola rosea (Roseroot)

Rhodiola has been traditionally used in Scandinavia and Russia. A review in the European Medicines Agency (EMA) Assessment Report classifies rhodiola as a “traditional herbal medicinal product” for the relief of stress symptoms. Studies suggest that rhodiola may provide support for stress-related fatigue and mild exhaustion. The dose in most studies ranged from 200 to 400 mg of standardised extract per day.

Maca (Lepidium meyenii)

Maca is a root vegetable from the Peruvian high Andes. Gonzales (2012) published a systematic review of the evidence and concluded that there are indications of positive effects on energy and mood, but the data remains limited. Most studies had small sample sizes and short durations.

Differences between maca colours:

Maca Colour	Studied Effects	Evidence Level
Yellow	General energy, mood	Moderate (most common in studies)
Red	Prostate health, bone health	Preliminary (mainly animal studies)
Black	Cognition, spermatogenesis	Preliminary (few human studies)

Important: Most studies on specific maca colours come from animal experiments or small pilot studies. Transferability to humans is limited. Gonzales (2012) emphasised that larger, well-designed clinical trials are needed.

Ginseng (Panax ginseng)

Ginseng is the longest-studied adaptogen. Its active compounds (ginsenosides) have been examined in numerous studies. The EMA monograph on Panax ginseng recognises a traditional use for states of exhaustion. Studies suggest that ginseng may positively influence cognitive performance and subjective fatigue. However, the effects are also moderate here and not equally pronounced in all study participants.

What the Research Actually Shows

An honest assessment: the evidence base for adaptogens is promising but not overwhelming. Many studies have methodological limitations:

• Small sample sizes: Often fewer than 100 participants
• Short study duration: Rarely longer than 8 to 12 weeks
• Heterogeneous extracts: Different manufacturers, different standardisations
• Funding: Some studies are funded by manufacturers

This does not mean adaptogens are ineffective. It means the effects are probably more subtle than often advertised. Anyone looking for the one supplement that makes stress disappear will be disappointed. Anyone expecting moderate support can find reasonable evidence.

Realistic Expectations

Adaptogens are not miracle cures. They may modulate certain aspects of the stress response, but they do not replace:

• Adequate sleep (7 to 9 hours)
• Regular physical activity
• A balanced diet
• Stress management strategies (breathing exercises, meditation)
• Professional help for serious conditions

The research group around Panossian emphasised that adaptogens work best as part of a holistic approach, not as an isolated solution.

Interactions and Precautions

Adaptogens are plant-based active substances and therefore not free of risks:

• Ashwagandha may in rare cases interact with thyroid medication and should only be taken after medical consultation in cases of autoimmune thyroid disease.
• Ginseng may affect the action of blood thinners.
• Rhodiola may cause restlessness or sleep disturbances in sensitive individuals.
• Pregnancy and breastfeeding: For most adaptogens, sufficient safety data is lacking. Use during these periods is not recommended.
• Medication: Anyone taking medication should consult a doctor before taking adaptogens.

Conclusion

Adaptogens are a fascinating field of research at the intersection of traditional knowledge and modern science. The evidence suggests that certain plants can modulate the body’s stress response. At the same time, a sober perspective is warranted: the effects are moderate, the evidence base still has gaps, and large-scale, long-term studies are lacking. Those who view adaptogens as part of a healthy lifestyle and maintain realistic expectations may benefit from the current evidence.

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Sources:

• Panossian A, Wikman G (2010). Effects of Adaptogens on the Central Nervous System and the Molecular Mechanisms Associated with Their Stress-Protective Activity. Pharmaceuticals, 3(1), 188-224.
• Gonzales GF (2012). Ethnobiology and Ethnopharmacology of Lepidium meyenii (Maca), a Plant from the Peruvian Highlands. Evidence-Based Complementary and Alternative Medicine, 2012, 193496.
• Bonilla DA et al. (2021). Effects of Ashwagandha (Withania somnifera) on Physical Performance: Systematic Review and Bayesian Meta-Analysis. Journal of Functional Morphology and Kinesiology, 6(1), 20.
• European Medicines Agency (EMA). Assessment Report on Rhodiola rosea L., rhizoma et radix. EMA/HMPC/232100/2011.
• European Medicines Agency (EMA). Community Herbal Monograph on Panax ginseng C.A. Meyer, radix. EMA/HMPC/321233/2012.