Ashwagandha: benefits, dosage, dangers, and how to choose it wisely

Accumulating stress, light sleep, "nervous" fatigue, difficulty recovering… Many are looking for a natural solution without falling for miracle promises. Ashwagandha ( Withania somnifera ) is one of the best-known plants in Ayurvedic tradition, often classified among adaptogenic plants : the goal is not to "stimulate," but to help the body better adjust to constraints (stress, mental workload, training, lack of sleep).

In this guide, you will understand what science says , how to take it , who should avoid it , and how to choose an effective and safe extract .

Ashwagandha: what exactly is it?

Ashwagandha root is primarily used , depending on the extract). Its most studied active compounds are the withanolides (a family of steroidal lactones).

Why do we talk about “adaptogens”?

An adaptogen is generally presented as a support for the stress response (particularly the HPA axis, cortisol , and resilience). In practice, this translates in some people to:

• a better “return to calm”
• an improvement in sleep quality
• a feeling of better tolerance to workload (mental or physical)

Benefits of ashwagandha: the most documented information

The most frequent uses relate to stress/anxiety , sleep , and sometimes performance . Clinical literature is growing but heterogeneous depending on the extracts, doses, and durations used.

Stress, anxiety, cortisol: the number one use

In the field, ashwagandha is primarily sought after for:

• chronic stress / irritability
• ruminations
• “stress fatigue”
• nervous tension

Expert advice : if your main problem is hyperactivity in the evening (difficulty "switching off"), favour taking it in the late afternoon/evening, and evaluate over 6 to 8 weeks with a stable dose (see dosage section).

Sleep: falling asleep and quality

The benefit is often indirect: by reducing the perceived stress load, some people sleep better.

A common mistake is increasing the dose too quickly "to help you sleep." This can increase the risk of digestive/sedative side effects without guaranteeing a better result.

Physical performance, recovery, “stable” energy

Many people use it for:

• recovery
• feeling of more regular energy
• adaptation to a high training volume

Tips :

• During periods of overload (work + sport), ashwagandha may be more relevant than a stimulant.
• If you are already drowsy during the day, start with a low dose and take it in the evening.

Dosage: how much to take, when, and for how long?

Clinical studies use varying dosages, but in practice standardized extracts are often taken daily.

Common dosages (practical guidelines)

Depending on the extract and the standardization, we frequently see:

• 300 mg/day (cautious start)
• 600 mg/day (often used in 1–2 doses)

Pro rule : it's not "more = better". Tolerance and standardization matter as much as quantity.

Morning or evening?

• Evening preferred : if main objective = evening stress / sleep / relaxation.
• Preferably in the morning : if the objective is better stability during the day (to be tested if there is no drowsiness).
• Split (2 doses) : if you are aiming for a more “smoothed” effect (morning + evening).

Treatment duration and time to action

• Realistic assessment: 2 to 4 weeks for an initial feeling, 6 to 8 weeks to properly judge.
• Take stock: perceived stress, sleep quality, energy, side effects.

With or without a meal?

Often taken with a meal if you have a sensitive stomach (reduces digestive discomfort). If you're looking for a more relaxing effect, taking it in the evening with dinner can be a good compromise.

How to choose an effective ashwagandha (and avoid unpleasant surprises)

all ashwagandhas are created equal: what changes the perceived effectiveness is mainly the extract , standardization and quality .

Quality checklist (to be applied before buying)

1. Standardized extract (e.g., % of withanolides )
2. Part of a plant (most often the root)
3. daily dose (mg/day)
4. Traceability / controls (heavy metals, contaminants)
5. Transparency : batch, manufacturer, analyses

Forms: capsules vs. powder

• Capsules : precise dosage, convenient, better adherence.
• Powder : flexible, but has a strong taste and dosage is less reliable if you don't have scales.

Standardization: why it's crucial

Two "600 mg" products can be very different if one is a simple root powder and the other a standardized concentrated extract. For results-oriented use, standardization is a key criterion.

Dangers, side effects and contraindications (read before starting)

Even when "natural," ashwagandha is not harmless. Adverse effects exist, and rare but serious cases have been reported, particularly affecting the liver , as well as issues related to interactions and the thyroid .

Possible side effects

Most reported:

• digestive problems (nausea, discomfort, diarrhea)
• drowsiness / sedation

More rarely, liver damage has been reported.

Warning signs (stop + medical advice): marked unusual fatigue, jaundice, dark urine, persistent abdominal pain.

Who should avoid it (or seek medical advice)

• Pregnancy/breastfeeding : not recommended
• Liver problems or a history of liver problems: increased caution
• Thyroid : can influence thyroid function → medical advice if hyper/hypothyroidism or thyroid treatment
• Hormone-dependent prostate cancer : caution (potential effect on testosterone/hormones)

Drug interactions: the serious issue

If you are taking any medication (thyroid, anxiolytics/sleeping pills, antihypertensives, immunomodulators, etc.), avoid "random" self-testing and seek medical advice.

“Pro” usage protocol (simple, measurable, secure)

Steps

1. Choose a standardized extract + transparent brand (analyses).
2. Start low (e.g., 300 mg/day ) for 7 days.
3. Adjust if necessary (up to 600 mg/day ) according to tolerance.
4. Maintain for 6–8 weeks without changing 3 parameters at a time (coffee, alcohol, other plants).
5. Measure: sleep (falling asleep/waking up), perceived stress, energy, digestion.
6. Take a break for 1–2 weeks if using for a long time, and reassess the benefit.

Mistakes to avoid

• Changing brands/dosages every week (the effect cannot be attributed)
• “Stack” with 4 other adaptogens from the start
• Ignoring digestion (often the first limiting factor)
• Continue despite hepatic signals (rare, but to be taken seriously)

FAQ 

Is ashwagandha dangerous?

Ashwagandha is generally well tolerated, but digestive side effects and cases of liver damage have been reported; it can also interact with certain medications and influence the thyroid .

Why not take ashwagandha?

It is not recommended during pregnancy/breastfeeding , and requires caution in case of liver problems , thyroid disease or according to certain treatments/conditions (e.g. hormone-dependent prostate cancer ).

When to take ashwagandha: morning or evening?

In the evening if the goal is relaxation/sleep; in the morning if you are aiming for better stability during the day (to be avoided if drowsy).

How long does it take for ashwagandha to take effect?

Often 2 to 4 weeks for an initial feeling, and 6 to 8 weeks to properly evaluate a treatment at a stable dose.

What dose of ashwagandha per day?

Frequent use ranges from 300 to 600 mg/day depending on the extract and tolerance. Ideally, start low and then adjust.

Conclusion

Ashwagandha is most relevant if your priority is to better manage stress , improve sleep and support better recovery —provided you choose a standardized extract , follow a gradual dosage contraindications seriously , liver, thyroid, interactions).

If you are undergoing treatment, pregnant/breastfeeding, or have a history of liver/thyroid problems, consult a healthcare professional before starting any treatment.