Finding your CBD dosage is a bit like finding your shoe size: there's no universal answer. Here's the method validated by clinical studies and used by professionals.
Why is dosage so individual?
5 main factors influence the effective dose:
- Body weight: higher weight generally requires higher dose
- Hepatic metabolism: genetic variations on CYP3A4 and CYP2C19 — some metabolise CBD fast, others slow
- Targeted indication: 25 mg often suffices for sleep, 300 mg for severe anxiety
- Product form: sublingual oil, vape, capsule — bioavailability varies 6-fold
- Individual tolerance: personal sensitivity to cannabinoids (often genetic)
- Desired effect obtained = minimum effective dose reached. Stop.
- Onset of side effects (excessive drowsiness, digestive issues) = step down one increment
- Above 300 mg/day without medical advice = stop, consult a professional
- 150 mg: no effect
- 300 mg: maximum anxiolytic effect
- 600 mg: effect equivalent to 300 mg (not better)
- Anticoagulants (warfarin, vitamin K antagonists)
- Antiepileptics (phenytoin, clobazam)
- SSRI antidepressants (paroxetine, fluoxetine)
- Immunosuppressants (cyclosporine, tacrolimus)
- Drugs with narrow therapeutic window
- 50 kg person, dose 0.5 mg/kg = 25 mg = 5 drops
- 70 kg person, dose 0.5 mg/kg = 35 mg = 7 drops
- 90 kg person, dose 0.5 mg/kg = 45 mg = 9 drops
- Crippa JA et al. "Translational Investigation of the Therapeutic Potential of Cannabidiol (CBD)..." Front Immunol. 2018.
- Millar SA et al. "A Systematic Review of Cannabidiol Dosing in Clinical Populations" Br J Clin Pharmacol. 2019.
- Larsen C, Shahinas J. "Dosage, Efficacy and Safety of Cannabidiol Administration in Adults..." J Clin Med Res. 2020.
- Birnbaum AK et al. "Food effect on pharmacokinetics of cannabidiol..." Epilepsia. 2019.
The "Start Low, Go Slow" method
This is the universally validated principle in cannabinoid pharmacology. Three simple steps:
Step 1 — Start low (days 1-3)
Initial dose: 0.25 to 0.5 mg/kg, divided in 2 intakes.
For a 70 kg adult: 10-20 mg CBD total/day, i.e. 5-10 mg morning and evening.
At this dose, many people already feel a slight effect. Keep a journal: note at each intake the effect felt on a 0-10 scale.
Step 2 — Evaluate for 3-5 days
Why wait? CBD has an 18-32 hour half-life. It takes several days to reach steady state in the blood. Increasing too fast = not seeing the previous dose's effect.
Step 3 — Increase by 5-10 mg increments
If no effect or insufficient effect: add 5-10 mg/dose. Re-evaluate after 3-5 days. Continue until reaching the desired effect.
When to stop increasing:
Dosage table by indication
For sleep
| Disorder severity | Typical effective dose | |---|---| | Restless sleep, light evening anxiety | 15-25 mg, 45 min before bed | | Moderate insomnia | 25-50 mg, 60 min before bed | | Severe insomnia / chronic pain | 50-100 mg, 60-90 min before |
For anxiety
| Anxiety type | Typical effective dose | |---|---| | Chronic generalised anxiety | 25-50 mg, twice daily | | Social anxiety / phobia | 100-300 mg acute (60-90 min before) | | Panic crisis | 50-100 mg acute |
For chronic pain
| Pain type | Typical effective dose | |---|---| | Mild joint pain | 25 mg, 2-3× daily | | Neuropathic pain | 50-100 mg, 2× daily | | Cancer pain (medical follow-up) | 200-400 mg/day, in several intakes |
For focus / concentration
| Goal | Recommended dose | |---|---| | Day focus, mild anti-stress | 10-20 mg, 1-2× daily | | Exam / study preparation | 25 mg, 60 min before session |
The CBD bell curve
Counter-intuitive but documented: increasing the dose endlessly does not increase the effect endlessly.
Crippa 2018 study on 57 patients with social anxiety:
Beyond the optimal dose, some effects may even reverse. CBD is a biphasic modulator: at low dose, it stimulates a mechanism; at high dose, it may suppress it.
Practical conclusion: don't give in to "more = better". Better to step down one increment if the perceived effect diminishes.
Special cases
Elderly (> 65 years)
Slowed hepatic metabolism → half dose. Start at 5 mg/intake. Increased monitoring.
Very thin or overweight person
The mg/kg is less reliable. Adapt by feel rather than strict calculation.
Co-treatment
Medical advice mandatory if you take:
Person with fragile liver
CBD is metabolised by the liver. At high prolonged dose, possible elevation of transaminases. Hepatic panel recommended before and after 3 months of regular use.
Frequent mistakes
❌ Starting too strong → excessive effect, dropout ❌ Increasing too fast → can't see the previous plateau ❌ Under-dosing unknowingly → 2 drops of 5 % oil = 2.5 mg = ineffective for most ❌ Mixing several sources without counting total CBD → involuntary overdose ❌ Expecting effect in 1 day for chronic anxiety → count 2-8 weeks
Practical tools
Quick dosage calculator
For a 10 % oil (= 1000 mg CBD per 10 ml = ~5 mg/drop):
For a 20 % oil: divide drop number by 2. For a 30 % oil: divide by 3.
Tracking app
Several apps (CBD Tracker, Hempica, NuLeaf) let you keep a digital journal: dose, time, effect. Very useful to adjust over time.