Based on the anecdotal evidence, there are four possible explanations for this mysterious condition.

The term wood lover paralysis (WLP) refers to a temporary state of muscle weakness and/or paralysis that begins several hours after consuming certain types of magic mushrooms (aka psilocybin mushrooms or psychedelic mushrooms). The phenomenon appears to occur only after ingesting magic mushroom species that grow on wood, hence the name wood lover paralysis.

WLP is reported most often for the species Psilocybe cyanescens and Psilocybe azurescens.1 It has also been reported for the following: P. allenii, P. stunzii, P. subaeruginosa, P. pelliculosa, and P. ovoideocystidiata.

Despite many anecdotal reports of WLP (see below), no controlled scientific studies have been conducted. As a result, there is no consensus as to either the cause or solution to this longstanding problem.

Below are some illustrative anecdotal reports about the symptoms and attempted treatments for WLP. Most of this information was found on blogs, such as Shroomery. This article also discusses the leading theories for explaining the cause of WLP.

One challenge in elucidating the WLP problem is distinguishing its symptoms from similar sensations caused by taking highly unreliable amounts of powerful psychoactive drugs. For example, some psilocybin mushroom users appear to confuse the “body load” sensation with wood lover paralysis. Although both result in “heavy” feelings in the extremities, “body load” does not include extreme symptoms of paralysis such as loss of motor control and facial drooping.

Symptoms of Wood Lover Paralysis

Below are some first-hand reports that are taken from popular magic mushroom discussion forums like those on Shroomery, Erowid, and Bluelight. Bold text shows the symptoms that appear to be consistent across all accounts. In summary, they are:

Loss of motor control, ranging from incoordination to complete paralysis Loss of motor function in face/eyes Delayed onset of about 4-6 hours Resolution of symptoms within 24 hours

“the ‘paralysis’ manifested as waves of losing most of the motor control of my limbs . If I was standing one minute, I was crumpled on the floor flailing about the next.”

. If I was standing one minute, I was crumpled on the floor flailing about the next.” About 4 hours into a trip, “I got half way to the kitchen and suddenly my legs felt like they were going to collapse. I sat down for 5 minutes, got up again, walked for a bit- and then my legs DID collapse . It was a little scary because I felt clear headed, there was no pain or numbness… just non-functional legs .”

. It was a little scary because I felt clear headed, there was no pain or numbness… just .” “I collapsed in the middle of a field. I couldn’t walk 5 blocks. My co-tripper couldn’t smile the next day. I have experienced many muscular problems on these two species [psilocybe cyanescens and psilocybe azurescens]. They effect these muscle parts/groups: eye, facial, esophageal, hand and leg…. I have never had similar effects on [cubensis].”

in the middle of a field. 5 blocks. My co-tripper the next day. I have experienced many muscular problems on these two species [psilocybe cyanescens and psilocybe azurescens]. They effect these muscle parts/groups: eye, facial, esophageal, hand and leg…. I have never had similar effects on [cubensis].” “First noticeable symptoms are blurred vision, hand cramping/numbness, then loss of facial/mouth movement followed by having a hard time walking then full loss of the ability to walk properly or even stand period .” Link.

followed by having a then .” Link. “during the comedown, well passed the peak, I experienced first a weird “jumping effect” in my vision where the center of focus in my vision would seem to spontaneously jump away from where I was commanding it to be, disorienting and blurring my vision. Then I experienced “clipping” of the energy in my legs – it was like the signal to walk or stand would flicker out, causing a lot of difficulty with walking (this effect went away when I would just sit down). And finally, there were weird twitchy contractions around the muscles that controlled the mouth that made regular speech difficult .”

where the center of focus in my vision would seem to spontaneously jump away from where I was commanding it to be, disorienting and blurring my vision. Then I experienced “clipping” of the energy in my legs – it was like the signal to walk or stand would flicker out, causing (this effect went away when I would just sit down). And finally, there were weird twitchy contractions around the muscles that controlled the mouth that made .” “My friend … would try to stand up and his legs would collapse like jelly….he was also getting weird facial contractions where his mouth would distort similar to a mentally disabled person .”

like jelly….he was also getting .” Onset of “about 6 hours or so after eating them “

“ “One time walking to the bathroom was a massive struggle , I probably looked like I had cerebral palsy … and once I did make it to the bathroom, I couldn’t even raise my arms more than a few inches, and my legs were trembling, barely holding my weight . My vision was blurred , and when I looked in the mirror, I was literally slightly cross-eyed with one pupil still heavily dilated and the other in a normal state (lol).”

, I probably … and once I did make it to the bathroom, I more than a few inches, and my . My , and when I looked in the mirror, I was literally (lol).” “The next day after a high dose trip I couldn’t hold a spoon properly, brush my teeth etc. “

“ “I was fine that night. The next morning I woke up and was having a hard time focusing my eyes and felt very uncoordinated….All of a sudden I completely lost control of both legs , and my hands got seized up weird and stuff. I was in the middle of the road in the campground paralyzed . My mind was clear but I couldn’t get up no matter how many times I tried….My hands were seized up and my face was numb and the muscles unresponsive for up to a couple of hours and it went away.”

and felt very uncoordinated….All of a sudden , and my weird and stuff. I was in the middle of the road in the campground . My mind was clear but no matter how many times I tried….My and my and the for up to a couple of hours and it went away.” “…my knees almost buckled under me. Major muscle weakness , I wouldn’t necessarily call it paralysis though.”

under me. , I wouldn’t necessarily call it paralysis though.” “Not full on paralysis, but I did realize how wobbly and weak my muscles were feeling under me.”

my muscles were feeling under me.” “I’ve experienced the [paralysis] situation after [consuming] fresh, dried and boiled (steeped) [mushrooms]. “

“I have had severe paralysis on ps cyanescens to the point I had to hit the floor because my muscles just gave out.”

The Histamine Hypothesis and Proposed Anti-Histamine Treatments

Below are several quotes illustrating the hypothesis that some sort of histamine compound leads to the symptoms of WLP.

Several people have proposed that WLP is related to “a histamine reaction,” suggesting that “eating Benadryl will fix it.”

“Benadryl (diphenhydramine) is commonly used to treat certain types of acute movement disorders”

Histidine exists naturally in many types of fish. It is converted to histamine via the enzyme histidine decarboxylase produced by enteric bacteria like Clostridium botulinum. Histidine breaks down to histamine which is not destroyed by boiling water. Concentrated histamine is likely the main culprit. “I have successfully treated 5 people including myself of the dreaded paralysis with simple anti-histamines. This has worked 5 out of 5 times over the last 10 years. While there are probably more factors involved, I believe that histamine is the main cause of the Azurescens paralysis.” Notably, the histamine hypothesis overlaps with the bacteria hypothesis. This is because some theories suggest bacterial contamination of the mushrooms creates histamine which causes the paralysis.

Some have drawn the distinction between (a) the molecule histamine itself and (b) molecules affecting one or more histamine receptors in the body. “I don’t think the cause is due to ‘histamine’ in the wood-lovers. We don’t know the toxin responsible or exactly how it works, but it is likely it has some affinity for the histamine receptors, and/or interferes with dopamine-modulated movement.” If the H1 blockers like Benadryl work as treatment, it is very likely that the H2 blockers cimetidine (Tagamet), ranitidine (Zantac), and famotidine ( Pepcid ) will work as well with less sedation. Benadryl and the other H2 blockers mentioned are available as over the counter medications. “As a potent antagonist to acetylcholine in muscarinic receptors, diphenhydramine is used to treat Parkinson’s disease-like extrapyramidal symptoms caused by antipsychotics. The muscarinic receptor antagonism leads to correction of levels of dopamine, the neurotransmitter responsible for control of motor function in the brain, similar to the effect of other antimuscarinic agents such as atropine.”



Side Effects of Unknown Chemical(s)

Some have suggested that the symptoms of WLP could be caused by a chemical (other than psilocybin or psilocin) that is present in certain kinds of magic mushrooms. This suggestion makes sense. The state of the art for psilocybin focuses almost exclusively on different mushrooms varieties instead of the molecules inside those mushrooms.

In terms of chemical understanding, the state of the art regards psilocin as the only active molecule with psilocybin serving as a prodrug for that active molecule. This macroscopic perspective overlooks many important chemical considerations, such as other active psilocybin derivatives and/or phenylethylamines. Further research into psilocybin chemistry — especially the chemical composition of each different species — would provide important insight as to the cause(s) of WLP.

The Bacterial Contamination Hypothesis

Some bacterial and/or microbial contaminations such as black rot are thought to be responsible for WLP.

“it is probably has something to do with bacteria(s) that create toxins. Botulism caused by the botulinum bacteria has been suggested to be the culprit, however, while botulism is possible, I am here provide a slightly different explanation to the issue at hand. “

“Botulism just doesn’t fit. If it was botulism people would be dying a lot more often and would most likely need antibiotics to help recover.”

“The build up of histamine caused by bacteria who are capable of producing histamine in spoiled food, particularly fish, clams, mushrooms, etc. I have heard that the more damaged your shrooms the more likely they are harboring bacteria that are responsible for producing the high levels of histamine.”

“I have been leaning towards the idea that the paralysis is due to the inhibition of the enzyme the breaks down acetylcholine. This causes an over-stimulation at a neuromuscular junction due to the excess of acetylcholine (ACh), as of a result of the inactivity of the AChE enzyme, which normally breaks down acetylcholine. The muscles stop responding to the bombardment of acetylcholine, leading to flaccid paralysis, respiratory failure, and other signs and symptoms reminiscent of organophosphate poisoning. Benadryl is a potent antimuscarinic (a competitive antagonist of muscarinic acetylcholine receptors). This could explain why taking it helps. It reduces the amount of ACh hitting the receptor and boom, you regain muscle movement and strength.”

The Dose Hypothesis

Perhaps the simplest hypothesis for WLP is that the user ingested too many mushrooms. The famous mycologist Paul Stamets explains, “the difference between a medicine and a poison is often the dose.” This is a basic tenet in the study of toxicology, referred to as “the dose makes the poison.” Any substance has a harming potential if an organism is exposed to enough of it. For example, the median lethal dose (LD50) of water for mice is 25,000 mg/kg.

However, WLP is not caused by simply administering too much psilocybin. First, the phenomenon appears to be caused by only certain species of wood-digesting psilocybin mushrooms. If the symptoms were caused by overdosing on psilocybin/psilocin, then those symptoms would also arise from people taking large doses of psilocybin mushrooms that do not grow on wood chips. For example, Psilocybe cubensis is probably the most popular psychoactive mushroom in the United States. It is very potent. And, it is almost certainly the most cultivated psychoactive mushroom. Nevertheless, people do not appear to get WLP by ingesting large amounts of this species. This fact strongly suggests that psilocybin and psilocin are not causing the symptoms. Rather, wood loving mushrooms probably contain other molecule(s) that are not present in all “magic mushrooms” (see the Chemical Hypothesis above).

**If you have experienced Wood Lover Paralysis, you can contribute to solving the problem by filling out this survey on Wood Lover Paralysis.