This article is part of our Kratom Guide.
TL;DR
- Mitragyna speciosa shows different effect profiles depending on the strain (red, green, white vein), which users describe as ranging from relaxing to activating.
- The main alkaloid mitragynine is a partial μ-opioid receptor agonist with GPCR bias and additional adrenergic and serotonergic activity.
- Onset typically occurs within 15–30 minutes, with effects lasting 3–5 hours, depending on preparation and individual physiology.
- The dose-response relationship is non-linear: according to user reports, lower doses tend to be more stimulating, while higher doses are more sedating.
- Kratom is legal in Germany (listed neither in the BtMG nor the NpSG), but requires responsible use — in particular, no combination with opioids, alcohol or CNS-depressant medications.
| Botanical name | Mitragyna speciosa (Korthals, 1839) |
| Plant family | Rubiaceae (coffee family) |
| Origin | Southeast Asia — Thailand, Malaysia, Indonesia (Borneo) |
| Primary alkaloids | Mitragynine (~66 %), 7-Hydroxymitragynine (~2 %) |
| Available forms | Powder, capsules, liquid extract |
| Legal status (DE) | Legal — not listed in BtMG or NpSG |
Kratom leaf detail — Mitragyna speciosa
Wikimedia Commons · CC BY 3.0
The Three Main Effect Profiles
Kratom is traditionally classified by the color of the leaf vein — red, green or white. This classification reflects differences in alkaloid profile arising from the leaf's time of maturity and drying process. The experienced effects vary accordingly. A detailed overview can be found in the spoke article Kratom Strains.
Red Vein: The Relaxing Profile
Users often describe red kratom strains as physically relaxing, calming and suitable for the evening. Many report a physical heaviness ("body-heavy") perceived as pleasant, as well as a reduction in tension. In surveys, red vein is mentioned particularly often for the late afternoon or evening — as a companion for winding-down phases.
Onset is described as occurring within about 20–30 minutes, with subjective duration of 4–6 hours. The comparatively high ratio of 7-hydroxymitragynine to mitragynine in matured red leaves could explain the relaxing profile, although research data here is still limited.
Mitragynine
Green Vein: The Balanced Profile
Green strains are considered in user reports to be a balanced middle profile between relaxation and mild activation. Typical descriptions include a subtle mood lift, social ease and a mild, not overwhelming alertness. Green vein is therefore often used during the day when neither pronounced sedation nor strong stimulation is desired.
Onset is similar to that of red vein; duration is often described as 3–5 hours.
White Vein: The Activating Profile
White strains are most often described as stimulating, focus-supporting and suitable for morning to midday use. Users in surveys such as Grundmann (2017) report increased alertness and concentration — a profile often associated with the traditional use as a work companion in Southeast Asia.
White leaves are harvested earlier, leading to a different alkaloid ratio; preclinical work suggests that lower mitragynine doses may have stronger adrenergic modulating effects.
Extracts: A More Intense Profile
Kratom extracts concentrate the active alkaloids — particularly mitragynine — to multiples of the amount contained in raw powder. Users accordingly report a faster onset (often 10–20 minutes) and a more intense subjective effect profile.
Due to this higher concentration, extracts are not suitable for beginners. The basic rule "start low" applies even more strictly here: the non-linear dose-response curve means that small differences in quantity can produce significant differences in effect. More on this in the spoke Kratom Extracts.
Dosage and Effect: The Basic Rule
The dose-response relationship of kratom is biphasic and non-linear — a central pharmacological feature that has been described repeatedly in research (Hassan et al. 2013; Singh et al. 2014).
| Dose Range | Reported Effect Profile |
|---|---|
| Low | More stimulating, alert, social, mildly focusing |
| Moderate | Balanced — mix of alertness and relaxation |
| High | Distinctly relaxing, physically heavy, sedating |
What matters is not only the amount, but also set and setting: individual physiology, stomach contents, daily form, emotional state and environment significantly influence the effect. Specific gram amounts are deliberately not given here, as individual sensitivity varies considerably.
How Quickly Does Kratom Work?
Onset depends significantly on the form of preparation:
- Powder tea (brewed): approx. 20–30 minutes
- Toss & wash (powder with water): approx. 15–25 minutes
- Liquid extract: approx. 10–20 minutes
The subjective duration is typically given as 3–5 hours, with red strains and extracts tending to have longer-lasting effects. Influencing factors include:
- Stomach contents (empty stomach → faster onset)
- Individual CYP3A4 and CYP2D6 activity (mitragynine metabolism)
- Hydration and electrolyte balance
- Tolerance development with regular use
Details on preparation methods can be found in the spoke Kratom Preparation.
What Research Says
The largest user survey to date comes from Grundmann (2017), published in Drug and Alcohol Dependence. In this study, 8,049 kratom users were surveyed about their usage patterns and subjective effects. Key results:
- The majority of respondents reported a positively experienced mood modulation.
- Users often described kratom in the context of everyday coping, relaxation and energy.
- Self-reports corresponded with the three classic vein profiles (red / green / white).
Complementary work by Singh et al. (2014) on traditional Malaysian users and Vicknasingam et al. (2010) provided further data on long-term use and tolerance. A comprehensive overview is provided by our spoke Kratom & Research as well as the technical article on Mitragynine.
Safety Information
Even though kratom is legal in Germany and the WHO (2021) in its pre-review recommended not to internationally schedule kratom, responsible use is essential.
Not recommended in combination with:
- Opioid medications (additive μ-opioid receptor activity)
- Alcohol and other CNS depressants (benzodiazepines, gabapentinoids)
- Serotonergic substances (MAO inhibitors, high-dose SSRIs)
- CYP3A4 inhibitors or inducers
Do not use in case of:
- Pregnancy and breastfeeding
- Liver or kidney disease
- Pre-existing cardiovascular conditions without medical consultation
General principles:
- Start low, go slow — especially with extracts.
- Take regular breaks to minimize tolerance development.
- Ensure hydration and adequate food intake.
- Discontinue use if unwell.
Legal details in the spoke Kratom & Law in Germany.
Back to the Guide
Sources
- Grundmann, O. (2017). Patterns of Kratom use and health impact in the US — Results from an online survey. Drug and Alcohol Dependence, 176, 63–70. DOI: 10.1016/j.drugalcdep.2017.03.007
- Singh, D., Müller, C. P., & Vicknasingam, B. K. (2014). Kratom (Mitragyna speciosa) dependence, withdrawal symptoms and craving in regular users. Drug and Alcohol Dependence, 139, 132–137. DOI: 10.1016/j.drugalcdep.2014.03.017
- Vicknasingam, B., Narayanan, S., Beng, G. T., & Mansor, S. M. (2010). The informal use of ketum (Mitragyna speciosa) for opioid withdrawal in the northern states of peninsular Malaysia. International Journal of Drug Policy, 21(4), 283–288. DOI: 10.1016/j.drugpo.2009.12.003
- Hassan, Z., Muzaimi, M., Navaratnam, V., et al. (2013). From Kratom to mitragynine and its derivatives: Physiological and behavioural effects related to use, abuse, and addiction. Neuroscience & Biobehavioral Reviews, 37(2), 138–151. DOI: 10.1016/j.neubiorev.2012.11.012
- Kruegel, A. C., & Grundmann, O. (2018). The medicinal chemistry and neuropharmacology of kratom. Neuropharmacology, 134, 108–120. DOI: 10.1016/j.neuropharm.2017.08.026
- World Health Organization (2021). Pre-Review Report: Kratom (Mitragyna speciosa), mitragynine, and 7-hydroxymitragynine. Expert Committee on Drug Dependence, 44th Meeting, Geneva.
Status: Last updated 2025. This article serves solely as botanical and ethnopharmacological information. It does not constitute medical advice and does not replace consultation with a physician. Kratom is legal in Germany (not listed in the BtMG or NpSG), but is not sold for human consumption.
Further Reading
- Kratom Guide: The Complete Plant Profile
- Kratom Strains: Red, Green & White Explained
- Kratom Preparation: Methods & Best Practices
- Kratom Research: What the Science Says
→ Mitragynine Compound Profile — chemistry & pharmacology

