Declared 25 Percent and Power Categories in Scientific Reviews

• How much evidence. 4 works from 2021 to 2025, all listed in the table below along with the model.
• What has not been shown. It has not been shown that a higher declared percentage on the label means stronger or better therapeutic effects. The evidence material on the potency of the raw material concerns almost exclusively adverse effects and non-medical use, not effectiveness.
• What you won’t find here. Dosage recommendations or strain indications. The selection is determined by the attending physician, and cannabis flower is a raw material dispensed only by prescription.
• How to read this. The result of a study on rodents or in cell culture does not directly transfer to a patient taking the flower, and the column with the model indicates what the work was actually about.

What exactly does the declared 25 percent on the raw material label mean?

The declared 25 percent is a value recorded by the manufacturer for the entire batch, not a measurement of the bag dispensed at the pharmacy. It refers to the total amount of tetrahydrocannabinol after heating the raw material and is valid with an allowable deviation of ten percent, meaning it realistically indicates a range from 22.5 to 27.5 percent.

In fresh flowers, the acidic form predominates, which only converts to the active form under the influence of heat. Therefore, the number on the label describes the potential of the raw material after heating, not the composition of the plant at the time of harvest. The relationship between what the manufacturer declares and what is shown by the measurement made on the sample is the subject of a separate page on the declaration 20 percent. Here, it is enough to remember that the declaration is a commitment to the documentation of the batch, not a reading from the package that the patient holds in their hand.

The deviation works both ways, so the ranges defined by neighboring declarations partially overlap. What this means for comparing items with each other is developed on the declaration page 18 percent. This page does not compare items available in trade: the current list of strains is maintained by the hub of this cluster, and the store has a separate category for cannabis flower.

How do scientific reviews categorize the potency of flower and where does 25 percent fit in this division?

Three reviews from this database categorize potency in three different ways. The first sets one boundary around ten percent, the second builds five ranges corresponding to what is actually on sale, and the third compares only stronger products with weaker ones. The declaration of 25 percent falls into the broadest category in each of them.

The review from Annals of Internal Medicine adopted one boundary: it considered a product with a high concentration to be one that provides more than 5 mg of tetrahydrocannabinol per serving or exceeds ten percent content, as well as everything described as a concentrate. With this definition, flower with a declaration of 25 percent is in the same bag as an extract with double the content. This boundary is supported by a review covering 99 studies and over 221 thousand participants, in which 42 percent of the works were randomized.

The review from the American Journal of Psychiatry took a different path and established five ranges before analysis, chosen to correspond to what actually reaches the market. They are compared in the table below. This is the only division in this database based on something other than the seller’s label. The authors sifted through 4545 records, leaving 42 observational and experimental works, and assessed the overall certainty of evidence as very low.

The oldest of these reviews, from The Lancet Psychiatry, does not use numbers at all: it divides the material into stronger and weaker as the studies included in the analysis did. Of the 4171 articles sifted, 20 met the criteria, all observational, involving humans.

Does 25 percent differ from 20 or 30 percent in this division?

No. In the division from the American Journal of Psychiatry, the range from 20 to 30 percent is one category, so declarations of 20, 22, 25, 27, and 30 percent fall into the same field. None of the four works in this database distinguishes anything within it by any result.

This single range covers the vast majority of Polish pharmacy flower. In this cluster, 85 cultivars carry 112 declarations of content, from 8 to 30 percent. Eighty-one of them fall between 20 and 30 percent, twenty-nine between 10 and 19, and two below ten. Fifty-four cultivars out of 85 have all their declarations within this one range.

No declaration in this collection exceeds 30 percent, so the two upper categories from the table above, those reserved for kief, resin, and concentrates, remain empty for pharmacy flower. All the material available to the doctor here falls within three lower ranges, and in practice mainly in one of them.

The lack of a common measure of exposure is not a criticism of the editorial team, but a note from the authors themselves. The team from The Lancet Psychiatry stated directly that such a measure is lacking, and the team from the American Journal of Psychiatry admitted that potency has sometimes been estimated from participants’ declarations and measured differently in each study. Therefore, they had to establish their own ranges before comparing anything.

How is the potency of raw material selected for the patient?

The attending physician decides, as we are dealing with a raw material dispensed only by prescription in the Rpw category. The number on the label does not directly translate to the serving: with the same declaration, a different mass of raw material and a different route of administration provide completely different exposure to the active substance.

The declared content speaks to the proportion, not the dose. The same mass of raw material with a declaration of 25 percent carries more active substance than weaker raw material, but how much of it reaches the body is determined by the method of administration and the size of the serving, and this is not described by the number on the label. Gradual approach to the serving, or titration, is developed separately on the declaration page 22 percent.

Tolerance changes the picture even more. The same item in two patients, one of whom has been taking the raw material for months and the other is just starting, is not the same exposure, and this difference is not visible in any number printed on the package. Therefore, the choice of potency is not a choice for the reader, but a decision made in the office, based on the interview and a complete list of medications taken.

Does the declared 25 percent change the onset and duration of action?

No. The onset and duration are determined by the route of administration, not the number on the label. The declared content indicates how much active substance the same mass of raw material carries, not how many minutes it takes for the effect to start or how long it lasts in the body.

The route of administration determines the course more than the strain itself. After vaporization, the substance passes from the lungs to the blood almost immediately, so the first sensations appear after a few minutes, the intensity increases for another ten to thirty minutes, and the whole effect wears off within two to four hours. After ingestion, the raw material first passes through the intestine and liver, so the first sensations are waited for from half an hour to two, and the episode lasts six, sometimes eight hours. Hence the most common mistake with oral administration: anyone who thinks after thirty minutes that nothing is happening and adjusts the serving will receive both doses at once. The above ranges describe the route of administration, not the strain; pharmacokinetic studies for a single cultivar have not been published.

The declaration thus changes the scale, not the clock. A separate matter is that the raw material studied twenty years ago was weaker than today’s: a review from the journal Addiction showed through a meta-analysis of subsequent years that concentrations have increased, so older studies describe material that is no longer available today. This thread is developed on the declaration page 30 percent.

What is known and what is not known about the relationship between raw material potency and effect?

It is known that higher concentrations are more often associated with the diagnosis of psychosis and cannabis use disorders. It is not known whether a higher declaration gives a better therapeutic effect: there are few works on medical use, their results are mixed, and the certainty of evidence was assessed as very low by the authors of two reviews.

The largest collection comes from Annals of Internal Medicine: a systematic review of 99 studies involving 221,097 people, of which 42 percent were randomized studies. In works outside the therapeutic context, an unfavorable relationship with psychosis or schizophrenia was shown in 70 percent of studies, and with cannabis addiction in 75 percent. For anxiety, this percentage was 53, and for depression 41, mainly concerning individuals without a diagnosis. Moderate or high risk of systematic error burdened over 95 percent of the included works.

The therapeutic side of the same review looks different: benefit for anxiety was found in 47 percent of works, for depression 48, but at the same time, 24 and 30 percent of these areas showed unfavorable relationships. The review from The Lancet Psychiatry, based solely on observational studies, saw an increased risk of psychosis and cannabis addiction with stronger products, and for depression and anxiety, considered the evidence to be inconsistent. The review from the American Journal of Psychiatry found a signal in the area of problematic use, while in other areas the results were less consistent, although they tended to lean towards worse outcomes with higher potency.

The fourth work, from the journal Addiction, does not measure the effect on the patient at all. A meta-analysis of subsequent years showed that concentrations in raw material have increased, and the conclusion from this is methodological: a study from decades ago describes material that is weaker than today’s, so transferring its results directly to today’s flower underestimates exposure.

What adverse effects are associated with higher potency raw material?

For the range including the declaration of 25 percent, there are no Polish data on frequency. National compilations of reports concern cannabis flower as a group of raw materials, and reviews dedicated to potency primarily describe non-medical use and psychological effects, so their percentages do not directly transfer to a patient with a prescription.

Reports of adverse effects are collected for medicinal products with a batch number, not for the strain name, so the following concerns cannabis flower as a group of raw materials. The most commonly reported effects are dry mouth, red eyes, and increased heart rate. Dizziness upon rapid standing, daytime drowsiness, and transient worsening of short-term memory are less frequently reported, as well as anxiety that increases with dosage. A separate matter is medications taken concurrently, especially sedatives and those affecting coagulation: their assessment requires knowledge of the entire list of preparations, not just the description of the plant. We do not provide numerical frequencies for these symptoms because public compilations for cannabis flower in Poland do not separate them by individual products.

The reviews referenced on this page speak to something different than the above list: to diagnoses made after years of use, not symptoms after a single serving. The relationship with psychosis and addiction was described there for stronger products as a group, without distinguishing declarations within it. Symptoms reported at higher concentrations are developed on the declaration page 27 percent.

Frequently Asked Questions about the Declared 25 Percent

Does a higher percentage on the label mean stronger therapeutic effects?

It has not been shown that a higher declared percentage on the label means stronger or better therapeutic effects. The evidence material on the potency of the raw material concerns almost exclusively adverse effects and non-medical use, not effectiveness, and works on therapeutic use are few and yield mixed results. The authors of both of the latest reviews assessed the certainty of evidence as very low. There is also no study that compared two pharmacy flowers differing only in declared content.

How much tetrahydrocannabinol can the flower with a declaration of 25 percent realistically contain?

With an allowable deviation of ten percent of the declared value, the range is from 22.5 to 27.5 percent. The result of the measurement made on a sample from the batch can fall anywhere within this range and still remain compliant with the label.

Is 25 percent a lot compared to Polish pharmacy flower?

This is the upper part of the declaration range. In this cluster, 85 cultivars correspond to 112 declarations, the lowest being 8 percent, the highest 30. There are none above 30 percent, so the categories reserved in the literature for kief, resin, and concentrates remain empty for pharmacy flower.

What is the difference between a declaration and the measurement result in a specific batch?

The declaration is a value assigned to the batch in the manufacturer’s documentation, while the measurement pertains to a sample taken from that batch. Compliance is assessed against the tolerance range, not against a single number.

Do reviews distinguish flower with a declaration of 25 percent from concentrates?

Only one of them does. The review from the American Journal of Psychiatry keeps concentrates in a separate category above 60 percent. The review from Annals of Internal Medicine sets one boundary at ten percent, and after exceeding it, does not further distinguish flower from extract.

Who decides on the potency of raw material in treatment?

The attending physician. The raw material is dispensed by prescription in the Rpw category, so the selection of the item, its potency, and method of administration is up to them, not the patient reading the description online.

Cannabis flower is a pharmaceutical raw material dispensed by prescription in the Rpw category, and the material is informational and does not replace medical advice.

The editorial text was prepared by the editorial team of ubucha.pl.