The use of marijuana whether for therapeutic or recreational purposes is punishable in Spain. Nevertheless, some 300,000 Spaniards use cannabis as a medicine, and although more and more doctors recommend its use, patients can only buy it on the black market or in a smoking club, or they can grow it at home, an activity that is not without risks.

According to Manuel Guzman, professor of Biochemistry and Molecular Biology at the Complutense University of Madrid, cancer patients make up the largest percentage of therapeutic marijuana users in Spain. Marijuana is effective in inhibiting pain and nausea associated with cancer and chemotherapy treatments.

Another cohort of patients who value the therapeutic properties of marijuana are those affected by neurological diseases of various kinds. Patients with multiple sclerosis, neuropathies, fibromyalgia, etc., use marijuana to ameliorate pain and stiffness in joints and limbs. It is also used to decrease seizures in epileptic-type diseases, especially in children where the effect is more pronounced than in adults.

Therapeutic uses of medical marijuana

It is very difficult to set a good dosage regimen since there are significant differences in the potency of marijuana from one variety and even one plant to another. They can contain different quantities and concentrations of active ingredients.

It is advisable to start with low doses of the variety available and gradually increase the doses until you notice the desired effect.

Therapeutic marijuana can be inhaled or ingested as an infusion.


This is the most direct route as the active substances enter the bloodstream directly through the pulmonary alveoli. Marijuana can be inhaled with a vaporiser, which volatilises the active ingredients. It differs from smoking in that the latter is more harmful due to the number of carcinogens and irritants in tobacco smoke.


If it is ingested in an infusion, the marijuana will take effect after about 30 minutes. The effect is at its strongest after about 2 or 3 hours and can last for up to 8 hours. One of the advantages over inhalation is that ingestion produces fewer unwanted psychological effects.

Try to keep to the same variety during treatment in order to adjust the dose. And wait at least two weeks before assessing its effectiveness.

In any case, the doses depend to a large extent on the person and their previous experience with cannabis.

Side effects

The side effects that medical marijuana users may experience vary from patient to patient. They depend largely on the quality of the marijuana, the way it is administered, the patient’s previous experience with the substance and their mood at the time of use.

Many patients describe a feeling of euphoria after taking it that gradually changes to a feeling of satisfaction and tranquillity. They also describe an increase in appetite, fits of laughter, atypical perception of time or space, feeling lazy and increased sensitivity in their perception of colours and music.

The effects on perception can cause feelings of confusion and panic especially in rare cases where these negative effects can be more pronounced.

Prolonged consumption of the substance can lead to concentration and memory problems.

Other adverse side effects include tachycardia, orthostatic hypotension, headache, dizziness, imbalances in thermal perception with alternation of cold or heat, red eyes, and depression of the locomotor system.

Benefits of medical marijuana

While the recreational use of marijuana is controversial, there is no such controversy regarding the benefits of medical marijuana as there are innumerable studies that demonstrate its virtues in the treatment of many conditions.

It is shown to be effective as an additional treatment for improving the symptoms of patients with moderate or severe spasticity associated with multiple sclerosis.

It is also known to relieve muscle spasms and pain in patients with spinal cord problems.

It is administered to cancer patients to treat pain and nausea caused by chemotherapy and radiation and to ease the side effects of retro-viral medication taken by HIV patients.

It is also effective for the treatment of chronic pain originating in the nervous system and Gilles de la Tourette Syndrome, where it helps to stop tics.