Skip to content


We answer all types of Neurology/Neurological questions about the brain, spinal cord, and peripheral nerves. Include your age, sex, current meds, and known diagnoses, upcoming/completed appointments, tests, or procedures. We are not physicians. We help explain medical terminology and give support.
Neurological Effects of THC (help)
An_256865 posted:
Hello WebMd. I'm aware that this is a rather controversial topic, but I'm hoping to get only professional and informed answers as I'm concerned and in need of some answers.

I've only used marijuana about four times in my life and I'm not a daily user by any means. The last time I used it however, I believe it must have been a much stronger strain than I'm used to and I ended up having a very bad time. My whole body started twitching uncontrollably and I was having some pretty severe panic attacks. Needless to say, I've sworn off the stuff forever since then. However, its been about two days since the incident and my legs and arms are still intermittently twitchy. Psychologically, I've been feeling slightly apathetic and zoned-out, like I'm not feeling things as intensely as I used to. I understand that it takes a while for the THC to completely leave one's system, and I was wondering how long that might be/ if what I'm feeling has been caused by that at all. Perhaps I'm just overreacting, but I'm a cautious person and I'd like to be sure. ANY professional non scare-tactic advice on the matter would be extremely relieving to me. Thank you.
lifes responded:
First, this board is not run by physicians. However, I and a couple others on this forum have a professional medical background. Many users also enjoy researching medical questions through medical journals online or other reliable medical websites.

Second, though more small medical-scientific studies have been done on marijuana use and specifically THC, it's status as an illegal drug means almost no studies with high (pun) populations, e.g. thousands of people versus just a small number of study participants. When studies include a larger sampling size, more factors can be reliably proven or disproven.

So what do studies show about THC and physical or psychological adverse effects? Note the small sample sizes. From a New Zealand a sample of 1000 people aged 18-25, 22% reported panic attacks or anxiety.

Now for a symptom like twitching, I could not find a reliable study to show here. What I found were self-reports on forums for the subjective 'sensation of twitching' without objective observation... to self-reports of one area of the body to whole body twitching during marijuana use. Self-reporters state that it was often severe enough to make them quit smoking; those who used again in the future reported that twitching returned each time. Twitching and spasm were often reported as meaning a similar sensation. (Google for symptom to read different user forums.)

However, as you may be aware, many people with MS or other muscle spasm / twitching conditions argue that marijuana helps their symptoms. How is it possible that the same substance can cause a negative symptom but be reported to relieve the same symptom? This mystery has no scientific answer yet. However, some herbs and regulated medications can and do produce the ''opposite" symptom... when these are identified, physicians can use a med deliberately to produce the usually 'unintentioned' effect. Second, with marijuana and other street drugs (and even herbal remedies), the answer may simply be that there is NO dose-regulation from one sample to the next sample, which can be a huge problem medically. Like you said, some property in what you used may have been much higher. Third, regulated drugs go through drug testing on thousands to millions of people to study effects among a large population, which helps drug companies know the common side effects at 10 mg versus 50mg etc. Since there's no large study of pot users, no one knows how it might affect different people. Your height, weight, metabolism, and your body's nervous system all play into how well you absorb and excrete any drug.

I found this website about drug excretion, but it's based on regular users:

From my reading, feeling zoned out, apathetic, and twitching are more often present with chronic use. So again, perhaps what you smoked was more potent, or maybe had some other substance mixed in? Drug dealers often substitute other 'stuff' to either cheat users--OR--to get a user hooked on the other substance--- a kind of "make the user buy again" strategy.

I would suggest, first, that you increase your fluid intake (water, juice) to help your system flush the metabolytes from your body. Second, you might consult your doc for a short term and small dose of muscle relaxant or sedating anti-anxiety med with effects on nerves/muscles. But bite the bullet and be honest about why you started twitching, so the doc can choose the right med and dose to help you. Third, all the forums I read, users stated they were too afraid to smoke again because it had been so scary and physically painful. Of those who smoked again, they reported the symptom re-occurred... and then, they stopped using.

I'm sorry I can't be of better help.


Spotlight: Member Stories

I'm a PA student, graduating in December (I hope). I have a long history as a patient including six unrelated surgeries, and a couple of other hos...More

Helpful Tips

It hurts! It jerks! My body's doing something...strange...
Every person with a neurological condition or disorder started out with a symptom that hurt, jerked (tremor or worse), or that just was ... More
Was this Helpful?
10 of 19 found this helpful

Report Problems With Your Medications to the FDA

FDAYou are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.