Does CBD Oil Make You Stupid?

With more people using CBD oil for anxiety, pain, sleep and stress, some are still asking: does CBD oil make you stupid? The short answer is no, CBD does not make you stupid. It doesn’t impair your intelligence, memory, or cognitive function, especially when used at recommended doses.

CBD (short for cannabidiol) is often confused with THC, the compound in cannabis that causes a high. But unlike THC, CBD is non-intoxicating, legal in the UK, and doesn’t interfere with clear thinking. Let’s look at the facts.

What Is CBD Oil?

CBD oil is a food supplement made from hemp extract, usually blended with a carrier oil like MCT or olive oil. It contains cannabidiol (CBD), a natural compound found in the cannabis plant that interacts with your endocannabinoid system—which helps regulate things like mood, pain, sleep, and stress.

CBD is not psychoactive, meaning it doesn’t alter your mind, make you high, or reduce your intelligence.

Does CBD Affect Brain Function?

CBD does interact with the brain, but not in a way that causes impairment. In fact, some studies suggest CBD may have neuroprotective properties and could support brain health by:

Reducing inflammation in the brain
Balancing mood and emotional regulation
Supporting better sleep, which improves focus and clarity
Reducing anxiety, which can help with concentration and decision-making

Unlike THC, CBD does not impair short-term memory, motivation, or learning ability.

Can CBD Make You Drowsy or Foggy?

In higher doses, CBD may cause mild drowsiness or relaxation, particularly if you're already tired or using it to help with sleep. Some people report feeling a bit “slowed down,” especially when first starting out.

But this is not the same as feeling "stupid" or mentally impaired. Most users describe it as feeling calmer, less anxious, or more settled—not foggy or confused.

If you do feel sluggish after taking CBD, it usually means your dose is too high or that you need to take it at a different time of day (e.g. in the evening instead of the morning).

Does CBD Affect Memory or IQ?

There is no evidence that CBD lowers IQ or damages memory. In fact, early research suggests it may even help protect against cognitive decline in conditions like Alzheimer’s or epilepsy.

This is in sharp contrast to THC, which can impair memory and focus, especially with heavy or long-term use. People often confuse the two—but it’s THC, not CBD, that’s linked with cognitive side effects.

Is It Safe to Take CBD Oil Regularly?

Yes, for most people, CBD oil is safe when taken responsibly. The UK’s Food Standards Agency (FSA) recommends a maximum daily dose of 70mg for healthy adults. Side effects are rare and usually mild, including:

Tiredness
Dry mouth
Light-headedness
Changes in appetite

These effects are temporary and usually resolve with dose adjustments. If you stick to quality, lab-tested products and follow dosage guidelines, CBD is unlikely to interfere with your thinking or day-to-day mental sharpness.

UK Legal Context

In the UK, CBD is legal as long as it contains less than 1mg of THC per container. High street and online CBD products are regulated as food supplements, not medicines, and must not make medical claims.

If you're using CBD and feel mentally foggy, it's worth checking the quality and ingredients. Low-grade products or those with unlabelled THC could be the real cause of any unwanted effects.

Final Word

CBD oil does not make you stupid. It doesn’t impair intelligence, memory, or judgement, and may even support brain health when used appropriately. If you’re feeling off after taking CBD, it’s more likely due to dose, timing, or product quality—not the CBD itself.

As always, listen to your body, choose trusted products, and speak to your GP if you have any concerns—especially if you're taking other medication or managing a health condition.