In brief
"Kratom for energy", "kratom for focus" or "strongest kratom" are among the most common searches people arrive with. You will not find a marketing answer to them on this website - deliberately. Since 12 November 2025 kratom has been a psychomodulatory substance, and the law prohibits sellers from making any claims about effects in connection with the product. This article explains what may be stated about effects, what the scientific literature describes and which widespread beliefs are myths. It is informational, not medical advice, and does not replace a consultation with a doctor.
Why a seller will not describe effects
The amendment to Act No. 167/1998 Coll. on addictive substances introduced the category of psychomodulatory substances; Government Regulation No. 456/2025 Coll. put kratom on their list and Decree No. 448/2025 Coll. sets the details of sale. For sellers this brings several restrictions that concern "effects" directly:
- the product must not carry health claims or any other claims about effects - not "gives energy", not "helps you focus", not "calms";
- expressions that imply an effect indirectly, such as "natural" or "vitalising", are banned as well;
- advertising must not target minors and must not encourage use.
So if you read somewhere that a particular strain "gives you energy for the whole day" or "relaxes you perfectly", you are reading a text that conflicts with the regulation - usually written by a seller who at the same time publishes no lab report for the batch. The absence of promises from a licensed seller is not a lack of information but a consequence of the law. More in Kratom regulation in Czechia.
What may be stated: the mandatory consumer information
The only wording about effects that may appear with kratom is part of the mandatory consumer information prescribed by the decree. It must be on every pack and we show it with every product. Here it is in full:
The key sentence is the first one: stimulating effects at the recommended dosage, sedative effects when it is exceeded. It says two important things at once - that the effect depends above all on the amount, not on the colour or name of a strain, and that exceeding the recommended dosage does not produce "more" of the same effect but a different, sedative profile. The rest of the text lists what may be affected (alertness, coordination, perception of pain, sleep, mood) and what the risks are. That is the entire scope of what can legally be said about effects - and it is more accurate than advertising shortcuts.
What the scientific literature describes
The following paragraphs summarise what scientific sources report - not what we promise. Effects vary by individual, batch, amount and circumstances and cannot be predicted for a particular person.
Alkaloids and mechanism
The main active substances are mitragynine and, in small amounts, 7-hydroxymitragynine. The pharmacological literature describes their action on opioid receptors (as partial agonists) and, for mitragynine, also on adrenergic and serotonin receptors. This combination is cited as the explanation for the dose-dependent profile: at lower doses mostly stimulant-like manifestations are described, at higher doses opioid-like ones including sedation.
WHO and EMCDDA assessments
The WHO Expert Committee on Drug Dependence (ECDD) carried out a pre-review of kratom in 2021. It concluded that the evidence was not yet sufficient for international control, but noted reports of dependence, withdrawal and poisonings, especially in combination with other substances. The European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) describes in its kratom profile the traditional use in South-East Asia, the dose dependence of effects and a growing number of adverse-effect reports in Europe. Neither institution describes kratom as safe or beneficial - they describe it as a substance with risk for which good long-term data are lacking.
Adverse effects and risks
The literature most often lists nausea, constipation, dizziness, sweating, loss of appetite and, with long-term regular use, dependence with withdrawal symptoms. Liver injury and seizures are described rarely; most serious cases involved combinations with other substances or uncontrolled products. See the detailed overview in Kratom risks and safety.
Common myths and what we know
"White kratom is for energy, red for relaxation"
Colour denotes the harvest stage and drying method of the leaf (kratom vein colours), not a guaranteed effect. Alkaloid content differs between batches of the same colour by tenths of a percent and in our reports the ranges of the colours overlap. The only thing that can be said about a batch with certainty is the value in the COA.
"There is a strongest kratom"
"Strength" is not a property of a strain but the alkaloid content of a specific batch - and that is measured, not promised. A strain with a higher average value in the reports (for example Maeng Da) differs from others by tenths of a percent; the dose you weigh out makes a bigger difference.
"Extract is better than powder"
Extract is more concentrated, not of higher quality. It has an order of magnitude more mitragynine per gram, its own instructions for use and is not interchangeable with powder. See Kratom extract vs. powder.
"Kratom for beginners"
No strain is "for beginners". The difference between products is the alkaloid content of the given batch; the same instructions for use and the same safety warnings apply to everyone. If you are unsure whether the product is suitable for you, consult a doctor.
"Kratom instead of medicines or alcohol"
Kratom is not a medicine, has not been clinically tested, and its combination with medicines, alcohol and other psychoactive substances is explicitly listed as dangerous in the mandatory information. The literature does not support replacing treatment with kratom; on the contrary, it describes cases where such use led to dependence.
"It is legal, so it is harmless"
Legal sale means a licence, tests, labelling and an age limit - not harmlessness. The mandatory information explicitly states that use may harm your health.
What this means for you
Instead of promises, a licensed seller gives you two things you can verify: a lab report for every batch with alkaloid content, heavy metals and microbiology, and instructions for use with a clear limit. Whoever promises you an effect instead is circumventing the law - and usually the testing too.
Frequently asked questions
Why do some e-shops describe effects?
Because they are breaking the regulation of psychomodulatory substances, or have not changed their texts since before it. Describing effects is grounds for sanctions for a licensed seller; for an unlicensed seller it is the least of the problems.
How long does the effect of kratom last?
The literature reports an onset within tens of minutes and a duration of several hours, with large individual variability. The course for a given person cannot be predicted; that is why the mandatory information prohibits driving for at least 8 hours after use.
Does white kratom have stimulating effects?
The mandatory information says the product has stimulating effects at the recommended dosage - regardless of colour. Colour does not determine the effect; the amount and the alkaloid content of the batch do.
Is powder safer than extract?
Dosing powder in grams according to the instructions is more transparent; extract is an order of magnitude more concentrated and a small measuring error means a bigger difference in alkaloids taken. Both products carry the same safety warnings.
Where do I find information about risks?
In Kratom risks and safety and in the Safety information section of every product.
References
- WHO Expert Committee on Drug Dependence (2021). Pre-review report: Kratom (Mitragyna speciosa), 44th meeting.
- EMCDDA. Kratom (Mitragyna speciosa) drug profile. European Monitoring Centre for Drugs and Drug Addiction.
- Prozialeck W. C., Jivan J. K., Andurkar S. V. (2012). Pharmacology of kratom: an emerging botanical agent with stimulant, analgesic and opioid-like effects. Journal of the American Osteopathic Association, 112(12), 792-799.
- Government Regulation No. 456/2025 Coll. on the list of psychomodulatory substances; Decree No. 448/2025 Coll.
