THC, CBD, cannabis flowers and extracts: what distinguishes these forms of treatment?

‘Medical cannabis’ sounds like a single treatment, but actually encompasses a wide variety of medicinal products. There are differences in composition, usage, available data and legal classification between dried flowers, a standardised extract and a ready-to-use medicinal product. This overview organises the terms so that you know what is being discussed during a consultation with your doctor.

Key points at a glance

• THC and CBD are two compounds found in the cannabis plant, each with different properties. THC has an intoxicating effect, whereas CBD does not.
• The most important practical difference between the various forms of therapy lies in standardisation, that is, in how precisely the active ingredient content is defined and verifiable.
• Study results apply initially to the product under investigation. They cannot automatically be extrapolated to any other cannabis product.
• Since 30 July 2026, dried flowers can no longer be prescribed at the expense of statutory health insurance, whilst standardised extracts, as well as dronabinol and nabilone, remain covered by statutory entitlement.

What lies behind the terms

THC and CBD are cannabinoids, i.e. compounds found in the plant. THC binds more strongly to receptors in the nervous system and is responsible for the psychoactive, i.e. intoxicating, effect. CBD acts on the same receptors much more weakly, does not cause intoxication and is being investigated, amongst other things, for its anti-inflammatory and antispasmodic properties. In a medicinal product, both substances are usually not present in isolation, but in a specific ratio.

Dried flowers are plant-based materials of pharmaceutical grade. The THC and CBD content is determined and declared, but the raw material remains a natural product with the corresponding range of variation. They are intended for inhalation using a vapouriser designed for this purpose.

Extracts are extracted from the plant and standardised to a defined active ingredient content. They are swallowed or absorbed through the oral mucosa.

Ready-to-use medicinal products contain a precisely defined active ingredient in an authorised dosage form. They have undergone a standard authorisation procedure and have an officially verified summary of product characteristics. The active substance dronabinol, i.e. isolated THC, is, by contrast, predominantly produced in Germany as a compound prepared in pharmacies and therefore does not belong to this group. The synthetic cannabinoid nabilone is the only cannabis-based medicinal product that remains subject to narcotics legislation.

Where the practical differences lie

• Composition: Dried flowers: plant material with a declared active ingredient content; extracts: standardised to a defined content; finished medicinal products: precisely defined active ingredient
• Standardisation: Dried flowers: limited, natural variations possible; extracts: high; finished medicinal products: very high
• Usage: Dried flowers: inhalation via a vaporiser; extracts: swallowed or absorbed through the oral mucosa; ready-to-use medicinal products: depending on the formulation
• Effective date: Dried flowers: relatively rapid, shorter duration of action; extracts: delayed, longer duration of action; ready-to-use medicinal products: delayed, longer duration of action
• Data status: Dried flowers: studies mostly on individual varieties and forms of use; extracts: studies on specific preparations; finished medicinal products: authorisation studies for the authorised indication

The information on the onset and duration of action describes a general trend, not fixed time values. No universally applicable figures can be derived from the product information, as these depend on the medicinal product, the method of administration and the individual being treated.

Nevertheless, the difference is more medically relevant than it might initially sound. For symptoms that occur in episodes or suddenly, a rapid onset of action plays a different role than for persistent symptoms, where a consistent effect throughout the day is the priority. Absorption via the gastrointestinal tract and the liver also differs from that via the lungs, which can affect tolerability.

What can and cannot be extrapolated from studies

Recent controlled trials have investigated very specific questions. A Phase 3 trial tested a full-spectrum extract for chronic lower back pain in around 820 adults over a twelve-week period, comparing it with a placebo. The difference compared with the placebo group was statistically significant, but the extent of the difference was moderate. A significantly smaller study investigated a vaporised formulation for acute migraine attacks in just over 90 participants in a cross-over design. A positive result initially applies precisely to this: to this preparation, this composition, this route of administration and this specific group of participants.

This leads to a rule that is often overlooked online. If a study shows that a standardised preparation is beneficial, this does not prove that a particular variety of the plant has the same effect. The reverse is also true. Statements such as ‘cannabis is effective for condition X’ are therefore almost always too vague to allow you to draw any conclusions for your own situation.

For you, this does not mean that one form is inherently better than the other. It means that the question of which form is appropriate can only be answered meaningfully in conjunction with the patient’s symptoms, medical history and tolerance.

Side effects: what is different and what is not

Typical side effects depend heavily on the THC content and are similar across all dosage forms. Dizziness and tiredness are listed as very common in the summary of product characteristics for an authorised cannabis-based medicinal product. Other commonly reported side effects include drowsiness, dry mouth, difficulties with concentration and memory, balance problems, gastrointestinal complaints, changes in heart rate and blood pressure, as well as restlessness or feelings of anxiety.

Differences arise primarily from the route of administration. With inhalation, an adverse effect sets in more quickly, but also subsides more quickly. With preparations taken orally, it may occur later and last longer. In addition, the impact on the respiratory tract is a factor that must be taken into account with inhalation.

Drug interactions affect all dosage forms. Of particular relevance are sedatives or depressants and active substances that are metabolised via the same pathways in the liver. A complete list of medications should therefore be discussed during the consultation, regardless of the chosen dosage form.

Prescription eligibility, reimbursement and clinician selection

Legally, the different forms are now treated differently. Dried cannabis flowers can still be prescribed, but since 30 July 2026, they are no longer covered by statutory health insurance. Since then, the statutory entitlement has covered cannabis extracts of standardised quality as well as medicinal products containing the active ingredients dronabinol or nabilone, although a six-month trial period of treatment with an authorised ready-to-use medicinal product containing cannabis is initially required. Approved ready-to-use medicinal products are reimbursed in accordance with the general rules governing the provision of medicines, within the scope of their authorisation.

The choice of medical treatment is determined independently by other criteria. These include the symptoms and their progression over time, pre-existing conditions affecting the respiratory or cardiovascular systems, other medication being taken, how easily a treatment can be integrated into daily life, and how well it has been tolerated so far. Only then does the question arise as to how the treatment will be billed.

As this assessment depends on many individual factors, it is best carried out by a practice with experience in cannabinoid therapy. Find doctors with experience in cannabis therapy

Frequently Asked Questions

Is CBD simply a weaker form of THC?

No. The two substances differ not in their potency, but in their mode of action. CBD is not psychoactive and interacts with the body’s endocannabinoid system differently to THC. They are therefore not interchangeable for medical purposes.

Which format is best?

There is no general answer to this question. The most suitable form of treatment depends on your symptoms, your medical history, your other medication and how well you tolerate it. It would not be responsible to give an assessment without a medical examination.

Are extracts safer than flowers?

Not in such general terms. Extracts are standardised more precisely, which makes their use more predictable. However, the fundamental side effects and interactions remain, and a delayed onset of action presents its own challenges.

Classification

The most important difference between the various forms of therapy is not their supposed potency, but how precisely their composition can be determined and how they are absorbed by the body. If you wish to apply information found on the internet to your own situation, you should therefore always check exactly which preparation is being referred to.

A medical examination will determine which treatment option is appropriate for your situation. View cannabis doctors by location