Compost and Pharmaceuticals


We get this question a lot–will pharmaceuticals end up in my compost if I use human urine or animal manure? This is really three questions:

  • Does composting break down pharmaceuticals?
  • Are some pharmaceuticals worse than others in terms of their ability to survive the composting process?
  • If pharmaceuticals persist after composting do edible plants uptake them in sufficient quantities to effect humans?

A look at what science has to say
We really need a Root Simple research department! I was able to find a few studies that, at least partially, address these questions. If you know of more please leave a link in the comments.

A 2010 study looked at the degradation of salinomycin, used on chickens to prevent coccidiosis. The study concluded,

On the basis of the results obtained in this study, it appears that the composting technique is effective in reducing salinomycin in manure.

Another 2010 study looked at the composting of sewage sludge containing fluoroquinolones (broad spectrum antibiotics),

The concentrations of pharmaceutical residues in compost were significantly lower, if compared to the relevant concentrations in sewage sludge . . . It is concluded that before using the sewage sludge compost as a fertilizer it should be carefully tested against the content of different pharmaceuticals. The content of pharmaceuticals in the compost made from sewage sludge may easily lead to the elevated concentrations in food plants, if the compost is used as a fertilizer.

A slightly contradictory Estonian study concluded:

In the current study, uptake of ciprofloxacin, norfloxacin, ofloxacin, sulfadimethoxine and sulfamethoxazole was demonstrated in lettuce. The uptake of fluoroquinolones and sulfonamides by plants like lettuce does not seem to be a major human health risk, as the detected levels of the studied pharmaceuticals were relatively low, if compared to their soil concentrations. Further studies are needed to determine the uptake of different types of pharmaceuticals and other organic pollutants by various crop plants.

What about hormones? A paper in the Journal of Environmental Quality concludes,

composting may be an environmentally friendly technology suitable for reducing, but not eliminating, the concentrations of these endocrine disrupting hormones at concentrated animal operation facilities.

But we’ve got a lot of hormones making their way into the environment due to agriculture, according to a study done by Temple University,

Animal manures (poultry manure and cow manure) contribute to a significant load of estrogen hormones in the natural environment.

Clearly we may have some big societal problems caused by the overuse of pharmaceuticals and waste generated by industrial livestock operations. Those issues are beyond the scope of this blog.

But what about home composting? Should I pee on my compost pile if I’m on lots of pills? Maybe not. But I think there are a few common sense guidelines we can follow when working with human and animal urine or manure at home:

  • Don’t use municipal compost that is made with sewage sludge, though I’m more worried about heavy metals in that compost more than I am about pharmaceuticals.
  • Since I’m not on any pharmaceuticals, I’m not worried about my own urine in the compost pile.
  • Joel, who commented on an earlier Root Simple post about using urine in compost, had this to say, “The main thing I’d worry about is radionuclide therapy, such as treatment with radioactive iodine vs. thyroid cancer. I guess I’d also worry a little about people who are on chelation therapy to flush toxic heavy metals from their system. If it’s not concentrated enough to harm your kidneys, though, I’m thinking it’s not enough to worry about in soil…perhaps that is me being naive.”
  • If I were collecting pee soaked straw bales at a French heavy metal concert (unlikely!),  I might have the resulting compost tested if I were going to use it on vegetables. But composting those bales would be better than flushing all that urine down the sewer system.

As to the bigger environmental issues, the good news is that some of the research shows that composting can help reduce pollution. And, since some of us have the space to compost at home, we can all contribute to a cleaner planet.

What do you think? Leave a comment . . .

Leave a comment


  1. “But composting those bales would be better than flushing all that urine down the sewer system.”

    I am skeptical about the merits of the straw bale urinals. How much pee can they hold before they begin to leak into the surrounding soil? Porta-Potties and modern waste treatment systems are probably the best way to deal with the massive amounts of human wee produced at a rock concert.

  2. in the idea of think global, act local, me and mine are recycling our urine waste. Reduce the amount of water we use in flushing and save it for the plants. reduce the strain on our septic system. Add important nutrients to our food growing system. The only medication used is hypothyroid meds which, even if they don’t breakdown, will not be enough to harm, and I’m the one taking them then eating the food, so the cycle continues. Thanks for all the info you’ve shared on this,

  3. At 65yo I take a few meds. My husband takes more but has little interest in the garden much less the compost pile and has a steadfast preference for the comforts of the bathroom. Meanwhile, I have been composting oleander from the time the hedge needed trimming and continuing through the period when they all died. There are stumps and roots of oleander breaking down right now and branches, stumps and roots that have been in my finished compost for years and years.

    Bottom line: if I’m not going to worry about oleander I’m not going to worry about what I voluntarily swallowed originally (some synthetic thyroid hormones and asthma meds) before I peed them into my pile and mulched them onto my veggies. …but then I’ve managed to get to 65 even tho I still remember what dirt tastes like from my preschool years.

  4. Interesting about the Oleander–I recently discovered that the big bushy plants I was throwing in my compost pile were poison hemlocks. I freaked and called the extension service. They advised bagging the compost and discarding it. I think I will just put it around something decorative rather than edible.

    I work in the drug rehab biz, and here’s what I know. 1. The quantities of Pharm or street sourced substances that exit via the urine stream are miniscule, and 2. What most commonly is leaving via the stream is a metabolite, not the drug itsself. The metabolite may well have few or no effects provided by the original drug that was consumed.

    I think “pharma-pee” it might screw up your organic certification, though, so if that’s your thing, maybe best to avoid it…?

    • Whatever makes you feel good and comfortable but I use my compost primarily for the edibles and mine has had oleander in it for almost the 15 years we’ve been living and gardening here out in the San Fernando Valley.

      No observable effects. So I’m more than good with it at this point. I’m not going to tell anyone else to put something which, in another circumstance, is toxic into their compost. But I’m not going to hesitate to rely on Mother Nature myself.

  5. Words like ‘reduce’ bother me. From what measurement is the reduction taken? I take estrogen and thyroid meds strong enough to stop all thyroid function. My pee probably is rather benign. LOL…see, I am minimizing my own involvement. However, there is no way I would ever use the pee of my friend who takes 17 meds, different pills each day–psychotropic, pain, and depression meds.

    Is this effort to minimize the residual drugs in the water/environment another GRAS? Maybe each person does not contribute enough for me to worry. But, at what point does a million or two frequent contributors into a system become a problem?

  6. Well, I don’t normally add my urine to the compost if I’ve taken anything at all, even something as benign (or so I think) as ibuprofen or aspirin. I just don’t feel comfortable with it. We’re on septic, so it does enter the groundwater eventually though, but hopefully in smaller quantities than it would uptake in my vegetables from the compost. Wish there was some good science out there regarding over-the-counter meds though, because I may be over-reacting to the threat.

  7. My two cents is just that it all goes somewhere, since there’s no such thing as “away”. Whether its in your compost or your soil or your water supply or someone else’s water supply or whatever. There’s no escape.

    That said, I think composting human waste (and animal waste, eg factory farm runoff) to catch that stuff is a really practical, workable approach. I believe in the power of compost to make many things right.

  8. Okay. I am loving these posts about peeing on compost. I have been directing my husband and his band mates to pee in my compost bin for years when they play and drink together – thinking giant amounts of corona can’t be THAT bad! But I didn’t know it was doing this much good!

    Hopefully none of them are taking andro-gel or something like that! 🙂

  9. “not saying”, I believe you have saved me from this episode of compost drama, right when things were heating up. :o) Twice I went out, fork and bags in hand only to hang my head and turn back–the idea of bagging a throwing out the heap felt akin to offing the family pets. Thank You!
    As for the pee, I think it may be less of a problem than either hemlock or oleander. The supposed issue with pharmaceuticals is in the water supply, from people flushing leftover (or felony-worthy) drugs down the toilet, or putting them in the trash. I don’t have any facts or figures about this, but it sounds like another good reason to install a rain barrel.

    • You can always put that particular compost on ornamentals and start a second pile for edibles.

      But, if it were me, I wouldn’t worry too much especially since I’d be willing to bet the hemlock is probably a small part of the whole pile. If that helps I’m delighted.

  10. My friend and I are trying to find out if manure (human, horse or rabbit) that might have GMOs in it (from eating non-organic food) are a threat to our organic garden. Do plants uptake GMOs?

    I was listening the a permaculture podcast with Dave Asprey of the Bulletproof Executive and he was talking about how fungicides were used in farming many years ago and that the fungi that survived have many toxins and are no longer consistently beneficial. Do GMOs mess up all the micro organisms and fungi that come in contact with it?

    If the plants that are growing in composted, non-organically fed human or animal manure, don’t uptake GMO cells but are surrounded by mutant soil microbes, are they healthy for us to eat?

    • I’m not a fan of GMOs, but I’m also not particularly worried about this issue. This is my opinion and some would disagree, but I think the problem with GMOs is that they encourage the overuse of herbicides and may have other unintended consequences. But I have great confidence in mother nature’s ability to compost organic matter and turn everything back into soil.

  11. The answer to sewage laced with pharmaceuticals and heavy metals alike may be gassification. Search the New York Times for the last year or two about this. A blast furnace is heated without oxygen within. Thus there are no dioxins produced. PCBs are broken down into harmless components far below the temperature reached in the furnace. This is not at all, not at all like incineration. Nothing is produced but hydrogen and methane, which are turned back to heat the furnaces. Heavy metals come out in the clinkers and can thus be safely recycled. It is of course a pity to lose the fertilizer, the humanure, they call it, which, in the absence of the phamaceuticals and heavy metals is made utterly pure by fermentation with sawdust and the like after two years. Smells of a German pine forest! While we clean up our act, volcanic ash is the ideal hard fertilizer according to the United States Geological Survey. Where ash falls on rainforest, colors are more intense! Does not pollute rivers, because “hard.” Just what our starving oceans need also. Vincent Shaw Flack

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