CBD Effects: How Cannabidiol Really Works (Study Results 2024/2025)

Key findings

• Proven effectiveness only in epilepsy: CBD is only approved as a medicine for certain forms of epilepsy (Dravet syndrome, Lennox-Gastaut syndrome) – for other uses, there is a lack of reliable clinical evidence.

• No effective painkiller: A high-quality study from the Medical University of Vienna showed that high-dose CBD is no more effective than a placebo for knee osteoarthritis. Although CBD is frequently advertised as a remedy for various ailments, the scientific evidence for these effects is currently limited.

• Promising results for anxiety and sleep: Smaller studies suggest positive effects on anxiety disorders and sleep problems, although often with significantly higher doses than in commercially available products.

• Consider interactions: CBD inhibits important liver enzymes and can increase or decrease the effects of other medications – medical consultation is important for long-term use.

• Quality matters: Without independent laboratory analyses, transparent manufacturer information and controlled THC levels, the effectiveness and safety of CBD products remain uncertain.

What exactly is CBD?

Cannabidiol, or CBD for short, is one of over 100 cannabinoids found in the hemp plant (Cannabis sativa L.). The abbreviation CBD stands for "cannabidiol"—not to be confused with the psychoactive THC, which causes the typical cannabis high.

The history of CBD research goes back further than many people realize. CBD was first isolated as early as the 1940s, but the intensive scientific investigation It only began in the 1990s with the discovery of the endocannabinoid system.

No intoxication, but modulation of the nervous system.

CBD is not psychoactive in the sense of producing a euphoric high. However, it does subtly influence the central nervous system. Users often report a calming effect, relaxation, and reduced anxiety – without getting "high." Unlike THC, CBD does not alter consciousness.

Origin and extraction

CBD is primarily extracted from the flowers and leaves of industrial hemp. These plants are specifically bred for a high CBD content and a low THC content of less than 0.2–0.3% (depending on the EU country). The cannabis plant yields various valuable components, the concentrations of which vary depending on the extraction method.

Full spectrum, broad spectrum or isolate?

CBD products are divided into three main categories:

Product type	Ingredients	Special feature
Full spectrum	CBD + other cannabinoids + terpenes + traces of THC	Potential entourage effect
Broad spectrum	CBD + other cannabinoids + terpenes, no THC	THC-free, but with plant extracts
Isolat	Pure CBD (99%+)	Only the active ingredient CBD

The so-called "entourage effect" describes the theory that various cannabinoids and terpenes are more effective when used together than when isolated. However, the scientific evidence for this is still limited.

Since around 2017/2018, CBD has experienced a strong market boom in German-speaking countries. Oils, capsules, and other products are available in online shops, pharmacies, and drugstores – however, the quality varies considerably.

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How does CBD work in the body? (Endocannabinoid system)

To understand the effects of CBD, one must... Endocannabinoid system (ECS). This endogenous regulatory system was only discovered in the 1990s and plays a central role in controlling sleep, pain, mood, appetite and immune function.

The basics of the ECS

The endocannabinoid system (ECS) consists of three main components:

• Cannabinoid receptors: CB1 (mainly in the brain and nervous system) and CB2 (mainly in the immune system)

• Endocannabinoids: The body's own messenger substances such as anandamide and 2-AG

• Enzymes: Responsible for the synthesis and breakdown of endocannabinoids

How CBD affects receptors

Unlike THC, CBD does not bind directly and strongly to CB1 or CB2 receptors. Instead, CBD works by indirectly modulating various systems:

• Anandamide degradation: CBD inhibits the enzyme FAAH, which is responsible for breaking down the "happiness molecule" anandamide. This allows more anandamide to remain in the body.

• Serotonin receptors: CBD interacts with 5-HT1A receptors, which play a role in anxiety and mood.

• TRPV1 receptors: These receptors are involved in pain perception and inflammation.

• GABA system: CBD can enhance the calming effect of the GABA system.

From theory to practice

These mechanisms theoretically explain why CBD could have effects on stress, sleep, and well-being:

mechanism	Possible effect
Increased anandamide	Reduced stress response, improved mood
5-HT1A activation	Less anxiety, calming influence
TRPV1 modulation	Altered pain perception
GABA enhancement	Easier falling asleep

Bioavailability and dosage form

The effects of CBD depend heavily on how it is taken. CBD is fat-soluble, so taking it with some fat improves absorption. Sublingual administration (under the tongue) partially bypasses the gastrointestinal tract and works faster than capsules.

Scientific research on CBD has increased significantly, particularly since 2013. Nevertheless, much of the findings still stem from animal studies or small human trials. Therefore, distinguishing between proven and presumed effects remains essential.

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Proven and probable effects of CBD (according to symptoms)

The quality of scientific evidence for CBD varies considerably depending on the area of ​​application. While some uses are supported by randomized controlled trials, others are primarily based on anecdotal evidence and animal studies. This distinction is crucial for realistic expectations regarding treatment. CBD is also used in some cases for headaches, although the evidence base for this is still unclear.

Well-documented effects: Epilepsy

The strongest evidence for CBD exists for certain forms of epilepsy. The drug Epidyolex received EU approval in 2019 for Dravet syndrome and Lennox-Gastaut syndrome in children aged 2 years and older. It is particularly noteworthy that CBD is specifically used to reduce the frequency of seizures in these forms of epilepsy, especially when conventional medications are not sufficiently effective.

The results of the approval studies are impressive:

• Randomized, double-blind, placebo-controlled trials in 24 clinics (USA, Netherlands, Poland)

• Significant reduction in seizure frequency within 12 weeks

• Lasting effect documented over 24 months

• Therapeutic doses: 10–20 mg/kg body weight per day

CBD is therefore the only cannabinoid with sufficient clinical research for regulatory approval in the pediatric population. The doses used are far higher than those offered by commercially available dietary supplements.

Promising effects: anxiety and stress

CBD shows promising potential for anxiety disorders, although the body of research is still limited.

Key study findings:

A case series with 72 participants, published in the Permanente Journal, showed that anxiety levels decreased within the first month and remained low throughout the three-month study period. In a controlled public speaking study, CBD reduced anxiety and cognitive impairment in previously untreated patients with social phobia.

A study with 11 participants in the Brazilian Journal of Medical and Biological Research also showed that CBD interacts with cortisol release and may block the release of the stress hormone.

Important NOTE: These studies often used doses of 300–600 mg of CBD – far more than the typical 10–30 mg in many over-the-counter products.

Promising: Sleep disorders

Many people use CBD for sleep problems, and smaller studies support this use:

• A double-blind study with 15 participants showed a significant improvement in sleep duration.

• The 72-participant study documented improved sleep quality alongside the reduction in anxiety.

The link between reduced restlessness in the evening and improved sleep onset seems plausible. However, clear dosage recommendations and large long-term studies are lacking.

Critical limitation: pain

A clear warning is necessary here: According to current studies, CBD is not an effective pain reliever.

A rigorous study by the Medical University of Vienna, published in The Lancet Regional Health – Europe, examined 86 participants with knee osteoarthritis over eight weeks. The result was clear: High-dose oral CBD showed no greater pain-relieving effects than a placebo.

The researchers explicitly concluded: “CBD is not an alternative for pain therapy in gonarthrosis.” If orally administered CBD in high doses shows no analgesic potential, topical CBD pain products should be viewed with particular skepticism.

Combination preparations containing THC (such as Nabiximols/Sativex) are better studied for chronic pain than pure CBD.

Early research: Mental illnesses

Preliminary evidence suggests that CBD has antipsychotic properties. However, studies on schizophrenia used extremely high doses of 800–1000 mg of CBD per day – this is a special case requiring medical and psychiatric supervision and is by no means suitable for self-medication.

Other research areas

Interestingly, a double-blind study with 24 participants showed that CBD users reduced their cigarette consumption by about 40%. Other areas such as gastrointestinal problems, skin conditions, menstrual cramps, and addictions are being researched, but so far there is insufficient evidence for general recommendations.

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Where and how can you feel the effects of CBD in everyday life?

The subjective perception of CBD's effects varies greatly from person to person. Genetics, metabolism, dosage, and product quality all play a crucial role. Most users report subtle "fine-tuning" of their well-being rather than dramatic effects.

Typical everyday effects at low to moderate doses

At daily doses of approximately 5–50 mg, users often describe:

• A feeling of inner peace without dizziness

• Less brooding in the evening

• Slightly easier falling asleep

• Subtle reduction for mild to moderate symptoms

• Generally improved well-being

Specific application examples

Presentation anxiety in the office: Some users take CBD 1–2 hours before stressful situations and report reduced nervousness. Scientific data on performance anxiety generally supports this use.

Sleep problems: Taking CBD oil in the evening before bed is one of the most common uses. Its calming properties can make it easier to unwind.

Recovery after sports: Some athletes use CBD for recovery, although the evidence for direct effects on inflammation in humans is limited.

Onset of effect and patience

Does CBD work immediately? Not necessarily. The effects often build up gradually over several days or weeks, especially with long-term oral use. CBD doesn't work like a classic painkiller "at the push of a button."

Expectation management

Be aware that expectations (placebo effect) and aggressive marketing promises can play a significant role.

Practical recommendation: Set a realistic goal and monitor the effects using a symptom diary (for 2–4 weeks). Record your symptoms, dosage, and any changes daily. This is the only way to objectively assess whether and how CBD works for you.

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What CBD products are available and how do they differ in their effects?

The CBD market offers a variety of delivery forms that differ in onset of action, duration of effect, and ease of use. Choosing the right form depends on your individual symptoms and lifestyle.

CBD oil and drops

Classic CBD oil is taken sublingually (under the tongue) and held there for about 60–90 seconds before being swallowed.

Advantages:

• Onset of effect usually after 15–30 minutes

• Good controllability via droplet count

• Flexible dose adjustment

Further information on current developments in the area Cannabis Trends in Germany 2025 You can find them here.

Understanding strengths: In a 10 ml bottle of 5% CBD, each drop contains approximately 2–2.5 mg of CBD. At 10%, it's about 4–5 mg per drop, and at 20%, correspondingly more. Calculate in advance how many drops you need for your desired dose.

Capsules and edibles

Capsules, gummy bears and other edible products are absorbed through the gastrointestinal tract.

Characteristics:

• Later onset of effect (30–90 minutes)

• Longer duration of effect (4–8 hours)

• Exact dosage per unit

• Tasteless and discreet – a possible alternative for cannabis enthusiasts

Ideal for people who don't like the taste of hemp or want to take CBD on the go.

Inhalation (vapes, CBD flowers)

Inhalation allows for the fastest onset of effects (1–5 minutes), as CBD is absorbed directly through the lungs.

Important warning: Medical societies view this approach critically. Risks include:

• Lung irritation caused by combustion products

• Fine dust from flowers

• Potential oil inhalation with low-quality vapes

Inhalation is not recommended for people with respiratory illnesses or concerns about lung health.

Topical application (creams, ointments, gels)

CBD creams are applied directly to the skin and work locally.

Areas of application:

• Skin irritation (eczema, acne)

• Muscle and joint pain

• Local relaxation

Systemic absorption through the skin is minimal. As mentioned previously, pain creams containing CBD should be viewed critically given the lack of evidence.

Combination preparations

Many products combine CBD with other substances such as melatonin, vitamins, or herbal extracts. With such combinations, it is often difficult to determine which component has which effect.

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Onset, duration and dosage of CBD effects

There is no standard dose for everyone. Body weight, metabolism, pre-existing conditions, and the target condition significantly influence the optimal dosage.

Onset of effect depending on the method of administration

Method of administration	Onset of effect	Duration of effect
Sublingual (oil under the tongue)	15–30 minutes	3–6 hours
Oral (capsules, edibles)	30–90 minutes	4–8 hours
Inhalant (vape, flowers)	1–5 minutes	1.5–3 hours
Topical (creams)	Gradually over hours	Locally limited

Practical example of an evening routine: If you want to use CBD for better sleep, take the oil sublingually about 1–2 hours before bedtime. For capsules, allow more time.

The dosing principle: Start low, go slow

The proven strategy for CBD beginners:

1. Start low: 5–10 mg per day

2. Observe: Stay on this dose for 3–7 days

3. Increase gradually: Increase by 5–10 mg

4. Stop: If the desired effect occurs or side effects occur

Therapeutic doses

For serious illnesses (chronic pain, anxiety disorders, epilepsy), therapeutic doses in studies often range from 100 to 800 mg daily. These amounts should absolutely be medically supervised and are neither practical nor safe to achieve with commercially available dietary supplements.

Recalculate dosage

Products often label their CBD content differently – per bottle, per ml, or per drop. Before buying, calculate how many mg you'll actually get per dose:

Example calculation:

• 10 ml bottle containing 1000 mg CBD = 100 mg/ml

• At approximately 200 drops per 10 ml = 5 mg per drop

• 4 drops = 20 mg CBD

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Risks, side effects and interactions

According to the WHO, CBD has a favorable safety profile, but it is not harmless, especially in high doses and with prolonged use. Honest risk information is important.

Typical side effects

The most common side effects are usually dose-dependent and reversible:

• Fatigue and drowsiness – especially at higher doses

• dry mouth – a classic cannabinoid effect

• Slight drop in blood pressure – can lead to dizziness

• Gastrointestinal problems – Nausea, diarrhea

• Changes in appetite – can gain or lose weight

• Headache – rare, can occur after taking CBD

Liver toxicity

Studies with high doses (over 20 mg/kg/day, as in epilepsy studies) showed increases in liver enzyme levels.

Recommendation: Liver function should be monitored by a doctor when taking medium doses daily (over 50–70 mg/day for several weeks).

Animal studies with very high doses also showed increases in liver, kidney, and heart weight, as well as effects on male fertility. These results suggest caution when using extreme doses.

Drug interactions

CBD CBD inhibits important liver enzymes, especially CYP3A4 and CYP2C19. These enzymes break down many medications. CBD can enhance or prolong their effects.

Drug group	risk
Blood thinners (e.g., warfarin)	Increased tendency to bleed
Antiepileptics	Increased side effects
Certain antidepressants	Changed effect
Immunosuppressants	Increased toxicity
Heart medication	Unpredictable effects

risk groups

Special caution is advised for:

• Pregnant women and breastfeeding mothers

• Children (except when Epidyolex is prescribed by a doctor)

• Older people with polypharmacy

• Patients with liver or kidney disease

• People with cardiovascular diseases

For these groups: Only after consulting a doctor and under no circumstances on your own initiative.

Quality risks

Even supposedly “harmless” CBD products from the internet can be contaminated:

• Pesticides and heavy metals

• solvent residues

• Higher THC content than declared

• Less CBD than stated

These contaminants pose additional health risks.

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Legal situation and quality criteria (Germany / Austria / EU)

The legal situation surrounding CBD is complex and changes regularly. This section provides an overview as of late 2024/early 2025, but does not replace legal advice.

Germany

Novel food status: CBD is considered a novel food. Without the appropriate authorization, its sale as a food supplement is not legally permissible. Nevertheless, numerous products are available on the market.

THC limits: Products may contain a maximum of 0.2–0.3% THC. The cannabis law amendments of April 2024 primarily concern the handling of cannabis itself, not the food and drug regulations governing CBD products.

Official assessment: The German Federal Institute for Risk Assessment (BfR) and state regulatory authorities have differing assessments of CBD products. Legal uncertainty prevails.

Austria

In Austria, CBD products are subject to stricter regulations. Since 2025, CBD flowers have been classified as tobacco products and may only be sold in tobacconists. Online sales are restricted or prohibited. The legal situation in this area changes particularly frequently.

EU perspective

At the EU level, CBD is not classified as a narcotic, but it is considered a novel food. Food supplements require approval procedures that many manufacturers have not (yet) completed. Numerous products exist in a legal gray area.

Quality criteria for consumers

What you should pay attention to when buying:

criterion	What needs to be checked
Laboratory analyses	Independent certificates with CBD and THC content
Purity tests	Heavy metal and pesticide testing
Origin	EU-certified industrial hemp
transparency	Full legal notice, batch numbers
Manufacturer's specifications	Clear declaration, contact option

Warning: Be skeptical of unrealistic promises of cures such as "cures cancer" or "replaces all medications." Reputable providers do not make such claims.

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CBD effects compared: oil, flowers, capsules & more.

While everyone talks about the "effects of CBD," practical experience varies considerably depending on the chosen form. Speed, intensity, and duration vary greatly.

CBD oil

This oil is excellent for testing individual dosages. It works relatively quickly and can build up a constant level in the body with regular use.

Typical use: Sleep problems, stress, chronic conditions

Advantage: Flexible dose adjustment, good control

CBD flowers

Flowers allow for a very rapid onset of effects, but smoking or vaporizing them poses health risks. They are also more legally problematic.

Important: Many doctors do not recommend CBD flowers due to the strain they can put on the lungs. The nature of the product (smoking) contradicts health goals.

Capsules and tablets

Capsules are ideal for people who prefer a neutral taste, precise dosage and discreet intake.

Nature of the effect: Gentler, slower onset, but longer lasting

Topical products

The effect is limited to the affected area. Systemic effects are minimal.

Fitness: Sports injuries, joint problems, irritated skin – as a supportive measure

Choice of form according to the objective complaint

Complaint	Recommended form
acute anxiety situation	Sublingual oil (fast absorption)
Chronic sleep problems	Oil or capsules in the evening
Local joint pain	Topical products (additional)
Daily basic care	Capsules (convenient, precisely dosed)

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Practical application: How to use the effects of CBD effectively

CBD is not a panacea, but it can be meaningfully integrated into a holistic health concept – along with sleep hygiene, exercise, healthy nutrition and stress management.

Steps for beginners

1. Define the goal: What do you want to achieve? (e.g., "fall asleep more easily", "less stress")

2. Select product form: A 5–10% oil is often suitable for beginners.

3. Start low: Start with 5 mg in the evening.

4. Observe: Stay on this dose for 7–14 days

5. Adjust: Increase the intensity carefully, if necessary.

Time planning

• Sleep problems: 1–2 hours before bedtime

• Daytime pain or stress: Distribute intake over 2-3 times

• When taking medication: Consult a doctor due to possible interactions.

Keep a symptom diary

A simple protocol helps with objective evaluation:

Date	Dose (mg)	time	Symptom severity (1-10)	Side effects
…	…	…	…	…

Keep this log for at least 2-4 weeks before making a final assessment of CBD's effect on your mind and body.

When to stop or consult a doctor?

Seek medical advice from:

• Severe fatigue that impairs daily life

• Persistent dizziness

• Persistent gastrointestinal problems

• Yellowing of the eyes or skin (liver problems!)

• Significant worsening of the underlying disease

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Conclusion: What one can realistically expect from the effects of CBD

CBD is an interesting plant compound with proven efficacy in certain forms of epilepsy and promising, though not yet conclusively proven, effects on anxiety and sleep. However, scientific evidence for its effectiveness in treating pain is lacking.

The effect varies from person to person. High-quality products, sensible dosage, patience, and medical supervision if needed make the difference between disappointment and potential benefit.

CBD does not usually replace conventional therapy, but it can complement it. Discontinuing important medications on your own in favor of CBD is dangerous and not recommended.

Remain critical. Question advertising claims. For serious conditions – whether depression, chronic pain, or neurological disorders – the development of a treatment plan belongs in the hands of medical specialists, not lifestyle blogs or sales platforms.

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FAQ: Frequently asked questions about the effects of CBD

Do you notice the effects of CBD immediately the first time?

Many people experience fatigue or mild relaxation the first time they take it, while others hardly notice anything. This is normal. Any potential effects often only become apparent after several days of regular use, once a certain level has built up in the body. Don't expect immediate, dramatic effects.

Can CBD be addictive or cause withdrawal symptoms?

According to current knowledge, CBD is not physically addictive and does not cause typical withdrawal symptoms like those associated with alcohol or opiates. However, psychological dependence is possible if CBD becomes the sole solution for stress management. A well-rounded approach to well-being remains important.

Will CBD use show up on a drug test (e.g., at work or by the police)?

Standard rapid tests look for THC metabolites, not CBD. Reputable products with very low THC content carry a small residual risk – especially with high doses or frequent use, minimal traces of THC can accumulate. Those who want to be absolutely certain (e.g., for professional checks, traffic violations) should use certified THC-free products (0.0% THC with a laboratory certificate).

Can I still drive a car or operate machinery while using CBD?

CBD itself is not intoxicating, but it can cause drowsiness and dizziness. Test your personal reaction first in a quiet environment. If you experience strong sedative effects, you should temporarily refrain from driving or engaging in dangerous activities. When in doubt, safety takes precedence over convenience.

Is CBD safe for pets and does it have a similar effect on them as it does on humans?

Dogs and cats also possess an endocannabinoid system, which is why CBD can theoretically activate similar pathways in the body. Special animal preparations with adapted dosages are available. However, administering human CBD products without prior consultation with a veterinarian is not recommended – the risks associated with dosage and quality are too high, and some additives in human products can be harmful to animals.