The dangers of Pawpaw consumption


From what I read, I believe occasionally eating Pawpaw will have a negligible effect unless someone has an allergy or genetic problem… The studies I’ve seen used large amounts of concentrated Annonacin. I didn’t see any that use the actual pawpaw fruit. Since they do contain a toxic substance I would only eat them occasionally until a better study is done. It’s a frustrating problem with all we eat. I now use the inferior tasting cinnamon because it contains less of the toxic substance in cinnamon. Then there is the toxicity of oxalic acid that is in many vegetables.

From KSU on the topic:

Kentucky State University asked the U.S.
Food and Drug Administration (FDA) for an
opinion on this topic, and their conclusion was
that pawpaw has a long history of food use
and the FDA does not currently have any
evidence that pawpaw is unsafe to eat.


If I remember properly from the last time we discussed this there was a study done with rodents and annonacin toxin. Just a few points to think about.

  1. You would need to eat 30 or more pawpaws a day for a month to get the same dose/kg as the rodents depending on the size and cultivar of the fruit.
  2. The toxin was intravenous bypassing the liver and digestive system. At the least the rate of absorption would be less in the digestive track giving your body more time to process it not to mention the liver may detoxify some of it, more research needs to be done.
  3. Toxins aren’t toxic at a linear rate. The annonacin in 3 or 4 pawpaws might actually be healthy for your neurons while 30+ pawpaws is toxic. This same property has been shown with radiation, a little actually decreases your chance of getting cancer.
  4. There was another study that showed that glucose (in the fruit) decreases the toxic effect of annonacin, as previously stated earlier these rodents were injected and not consuming any sugars.

I am however concerned with the herbal industry selling pawpaw bark as a supplement, I think this is a bad idea.


Perhaps he smoked some ganja before shooting that video. :woman_shrugging: He doesn’t look that out of the realm of normal in that video, to me. I’m no doctor, though…


I would see what the experts say. Kentucky State University has the largest research program on pawpaws in the world.


Let me start this by absolutely, utterly stressing that i see actininogens or whatever it was as a concern. Any neurotoxin gives me pause, one that MAY have been involved in related cases in the tropics even moreso.

All that said, there appears to be evidence these compounds are toxic. But the (huge) disconnects are in “human dosage” and acute vs chronic…there is almost no info on what a person would actually ingest and would get by first-pass effect and enter the blood vs the handful of cell-culture studies folks are freaking out about.

Again i really want to stress i believe in caution, but there is a sh!t-ton of variables at play here and we are sorely lacking in info…given whole-fruit puree studies on cell culture for example, cherries and spinach would both go from superfood to death-bomb (cyanides and nitrates, respectively) but the really, REALLY important things are dose, clearance, etc. etc., etc…

Are pawpaws worse than a nice not-actually-deadly spinach salad? Maybe. Maybe not. But so far we knoe if you give a boatload of pawpaw extract to cultured neurons its a problem. And we know if you eat a pawpaw relative borderline obsessively, you can get neurological issues.

We dont know

How plasma or csf levels of these compounds correlate to those used in culture experiments

Long-term, chronic effects vs acute toxicity, which seems to be what keeps getting published

Clearance rates, dosage rates, relative abundance of these compounds by cultivar, etc…,

Like i said i intend to be cautious…but for folks claiming proof it is safe OR dangerous, no such thing…we just dont have enough info, and if you werent sure google tomatidine, cyanide, atropine, , etc ad nauseum for possible toxins in “healthy” foods. Sometimes there are toxins present you simply dont absorb, or that you do but metabolize, or they are at insignificant levels…but the point is we just dont know.

Is it a good time to exercise caution? Probably.

Is it a good time to pretend we know…anything? Not if your own narrative means anything to you, i dont think, there Is just too much we don’t know. But as a guy who got his phD degree from the department of pharm and tox, There is way too much stuff up in the air right now with Pawpaws to say anything conclusive on either side. Eat them; dont, use moderation…I intend to be cautious But I don’t think there’s anywhere near enough information to draw a conclusion in either direction and pretending otherwise probably doesn’t help anything.


I would agree with that, most have no chance of any ill effects. But with that said, losing the nerve cells in the brain that control my coordination are very valued by me. Other toxins, and substances, probably do the same. And effect of losing a few cells, builds up with time. I’m not going to knowingly ingest substances that contain Annonacin. Annonacin is 100 times more toxic than 1-methyl-4-phenylpyridinium (MPP+), another potent mitochondrial complex I inhibitor.[5] Compared to MPP+, annonacin produces a wider and more dramatic loss of neurons, not only in the nigro-striatal system, but in the basal ganglia and brainstem nuclei as well.
I worry I might have other exposures, I just can’t knowingly ingest Annonacin. I don’t care how small of an amount. Cyanide is harmless compared to this compound. You can recover from cyanide toxicity, not so with Annonacin. So foods with cyanide I could care less. It even is used in medicine as a medication in certain emergency situations.


Friends of the Pawpaw,

I take Lithium under doctor’s orders. It is a toxic medicine. Tremors are the most common side effect. I had no idea that people were talking about this, without talking directly to me. One person has brought this to my attention. I think the stories circulating about me suffering atypical Parkinsonism should be a cautionary tale against jumping to conclusions.

We should remember the many illnesses that can cause tremor. My mother had a tremor in her hands since she was at least 30; it was a genetic condition. My case is different. I suffer from cluster headaches, the most painful headaches known to humans, worse than migraines. There is no cure. In my case the headaches are chronic, with one or two a day.

It is sheer torture, as you will see if you read Wikipedia. Since there is no cure, I am on prophylaxis (Lithium) to prevent their occurrence. When I taper off the Lithium, which I do from time to time, the tremors disappear. The neurologist who cares for me has tested me for Parkinson’s and said I do not exhibit the tell-tale symptoms; he says my tremor is consistent with Lithium.

I wonder how I contribute to this discussion of toxicity. I think you many consider me a pawpaw nut and totally defensive of the fruit. I am a nut, but I am equally a scientists. Proper realistic studies have not been done. Injecting rats with purified compounds is not realistic. The annona fruits and asimina fruits have been eaten by humans for eons. In my mind, so long as consumption is moderate and in season no lasting harm incurs. I am more concerned about allergic reactions.

Signed, Neal Peterson
you may communicate directly with me thru my website,


I am prescribed Lithium for my cluster headaches. It works at high dosage, and it gives me tremors. That is its common side effect.

Neal Peterson

I’d really like to know why no one contacted me about the tremors in the video. Somebody said “you would think he would speak up and tell people his symptoms have nothing to do with pawpaw consumption.” I am not a mind reader. Now I wonder what is the best way to address the concerns of anyone watching the video, to explain my illness and Lithium tremors. I welcome advice this group if you have ideas.


No one has brought this to me attention until today. Could you have written me with your concern. It is not possible for me to know what is discussed on this site, to which I have not been a member till tonight. The answer is: I have a medical condition that requires Lithium, the most common side effect is tremors. People assumed Parkinson’s. It is so wrong to assume. Now people will assume from the Lithium that I have bipolar syndrome. Wrong again. Do not make assumptions. My illness is Chronic Cluster Headache. I only put up with the Lithium because the headaches are worse. I’ve gotta go. Is late. Bedtime.

Neal Peterson
contact me through the website


I get horrible migraines very often. I’d never heard of Lithium for cluster headaches, but that’s excellent! Even with the side effects, I’ll say, because frequent horrible headaches are just too painful to bear. It really is awful.

I hope your headaches get/stay better! Your health is certainly your business, but now I can suggest Lithium if I ever meet anyone with cluster headaches, so that’s helpful to know.


Did you ever try magnesium instead of lithium? In contrast to lithium, magnesium is not toxic and in general beneficial to health, including both nervous and cardiovascular systems. One issue with magnesium is that high dosage needed for headache prevention produces a strong laxative effect (tolerance of magnesium in terms of its laxative effect can vary significantly between individuals).


Look into benefits of magnesium (specifically, organic magnesium salts).



As one of six moderators of this forum, I want to welcome you to this forum. This is the most active fruit forum on the internet.

People naturally draw conclusions with limited information. I’m really glad you got a chance to clarify and clear things up about your video.

You’ll see in the archives there has been a fair amount of discussion about pawpaws. I, myself have two pawpaw trees and look forward to the fruit every year. The fragrance, flavor, nothing else is like it.

Again, glad you jumped in here and hope you have more comments in the future.


Our water in newport, RI is unpotable. You can turn on the tap snd smell bleach.


Thanks for explaining what the cause is,Neal.
Now I’m concerned about the Lithium.A friend who is bipolar,took it for about twenty years,because it was the only thing that worked at the time.
Eventually it wiped out his kidneys and he had to go on dialysis and get on the waiting list for an organ.
Hopefully they will find a better and safer treatment for your headaches.
Thanks also for your research and contribution with this interesting fruit. Brady


to be honest I am not suggesting you eat a bunch of pawpaw, and will most likely eat it in considerable moderation myself. That said, my point was there’s just a lot of holes yet; yes its toxic but there doesn’t appear to be much info on absorption and excretion, the levels one would expect to be acutely or chronically toxic, or what kind of fruit intake would be required to exhibit either one. It is toxic in rats, but is it in humans (I suspect it is) and more importantly, would you actually see toxic levels from normal consumption?

Yes it was shown to be more toxic than MPP+ (if I remember correctly, that was the chemical most famously publicized from a bad batch of impure meth and a forensic tv show’s “case of the frozen addict” episode) in acute studies, and that’s enough that like I said I won’t be sitting down to pounds of the stuff all fall, but that doesn’t address chronic toxicity (which is likely far lower for either compound) and it also doesn’t address human intake and excretion/“bioburden” and what sort of levels you would have in your system from say 1 Overleese per day for 2 months out of the year. It could be far, far lower than what would actually prove toxic, and I’m not endorsing any poisons, but your mitochondria are exposed to low-level toxins constantly…not a good reason to bath in them, but context is important. Methanol, or specifically formate, is a mitochondrial poison. And you make it, every minute of every day, in your own body. Just at levels far lower than induce mitochondrial disregulation and cell death. (except see “Cuban nutritional amblyopia” if you’re curious, there was nutritional cases of what looked like methanol toxicity that were actually folks with too many smokes, too few B vitamins, and overall poor nutritional health)

Like I said, there’s a lot that just isn’t known. Given pawpaw is such a niche fruit, I doubt there ever will be.

But for now there’s folks claiming the sky is falling and others saying it is utterly harmless, and I don’t think there’s enough info to firmly decamp on either side of this particular river…


@RNeal you’ve already seen my posts here suggesting that, to me, it made no sense for people to be speculating about your health and especially about the cause of your health issues if you had any. I’m so glad you took the time to come here and open up bout something so personal - which happens to support my position on the matter.

But most of all, I just want to do what @Olpea did, which is to welcome you to You are something of a superstar around here! Lots and lots of people talk about and appreciate all your years of hard work in this field. I myself have 2 of your pawpaws and am proud of them. There are endless discussions about paw paws and paw paw growing here, and I’m sure you would enjoy reading them all-especially since you are mentioned in some of them. In fact, I would honestly think that there would be a lot of things on this web site that would interest you and bring you some enjoyment. It is an extremely active fruit growing site with lots of great people with all levels of experience. Don’t blame the whole site because a few people made some unfounded assumptions about you and your health and paw paws. We are a great group of people overall and would love to see you come around more often! And btw, I think your explanation here will go a long way in getting the word out to the rest of the fruit world who might think pawpaws caused your tremors. People here are active in many other fruit growing groups.

Thanks again and welcome.


Thank you! I’ve never taken that form, but the regular vitamin kind do help prevent them some… I just also get the side effect you mentioned, badly! I should try different forms and see which I can handle the large enough doses of.

(I’m on other meds for them, too, of course, which help keep the intensity down a lot, but unfortunately the class that helps so many people with migraines doesn’t help mine.)

Mr. Peterson, I’m another member here who is a huge fan of your work! I didn’t want to seem starstruck, lol. I’ve actually never eaten a pawpaw yet but I’m growing two trees :slight_smile: My neighbors remember wild ones from their youth and are quite excited, too.


Stan and Kevin,

I appreciate your solicitude.

All you have to do is read online the trustworthy sites about cluster headaches. No where is magnesium a palliative / prophylaxis for cluster headaches. I have been under the care of a respected neurologist for 9 years.
The tremors didn’t start for about 3 years.

It is so refreshing when I take a drug holiday, and am free of the side effects, even tho the headaches return. After a week I have to resume the medicine because of the pain.

Maybe you can let others know the nature of my illness, is unrelated to pawpaw consumption, in my doctors opinion. And in my opinion.



Welcome Neal,

I’ve gotma couple of your pawpaws as well.

Thank you for your breeding and the work youv done with the fruit.

Any new projects or varieties with which to tease us?