Permethrin vs. Pyrethrum: What’s the Difference?

Permethrin and pyrethrum insecticides are quite similar. It’s no coincidence that their names sound alike. They have similar qualities and chemical composition. They both kill unwanted insects. However, they are not the same thing.

So, let’s explore the topic of permethrin versus pyrethrum to see what makes them so different from each other and to find out which one is better for whatever your intended use may be.

Permethrin uses

Permethrin is a synthetic chemical used in insecticides to kill mosquitoes and other insects. It is also used in medications that treat scabies and lice. In animals, it is used to eradicate lice and other parasites which may be in their fur or, even worse, living inside of them.

Permethrin insecticides are available in creams, lotions, sprays, powders, flea collars, and treated clothing. Even though this pesticide can be found in medications and is meant to be applied to the skin, it can cause skin irritation. However, it is not dangerous or unsafe for adults or children over two months of age. Permethrin is, however, highly toxic to aquatic life (e.g., fish, frogs).

Permethrin insecticides should be used only when necessary and in the correct amounts, as is true for all medications and pesticides.

If permethrin is used according to the safety instructions, side effects are unlikely.

Permethrin is also utilized in agriculture where it is used to fight the pests that may infest various different crops. But, as it is a wide spectrum insecticide that is intended to kill various kinds of pests, it also kills beneficial insects such as honey bees. It can also be harmful to aquatic life.

Permethrin is used to fight insect pests, such as ticks, which may infect other animals by being applied to the rodent populations which may house these insects.

In addition, permethrin is used in tropical areas as a mosquito prevention measure to suppress deadly mosquito-borne illnesses such as malaria. By lining our bedding and clothing with this chemical, we can repel mosquitos and other insects that transmit different illnesses and infections. 

Pyrethrum uses

Pyrethrum is a natural insecticide found within a genus of flowers commonly called chrysanthemums. As it is naturally accessible, pyrethrum has been used for centuries.

Moreover, because pyrethrum is a natural plant extract, pyrethrum insecticide is non-synthetic and also can be used on certified organic farms.

Chrysanthemum flower

Chaleow Ngamdee/Shutterstock.com

Chrysanthemum flowers are dried and crushed so that the active components, called pyrethrin, can be extracted and the insecticide acquired. Nowadays, pyrethrum is combined with other chemicals for greater effectiveness and can be found in many household pest control products.

Even though pyrethrum is natural, pyrethrum insecticides are still dangerous for some animals, especially aquatic animals. Therefore, pyrethrum should be handled with the same amount of caution as synthetic pesticides because its toxic effects are quite similar to those of synthetic pesticides.

People who suffer an over-exposure to pyrethrum can experience side effects such as itchy skin, a runny nose, and even asthma symptoms. People who are sensitive and have allergies should be extra careful around chrysanthemums and pesticides manufactured from them, as they can cause health issues.

The differences between permethrin and pyrethrum

Permethrin and other pyrethroid insecticides are a modified form of pyrethrum.

Pyrethrum is the raw, natural form of this insecticide while pyrethroids were created to substitute this strong natural insecticide and to be more stable.

Pyrethrum breaks down rapidly in water or when exposed to light. Pyrethroids, however, are more resilient. As an insecticide, pyrethroids are still deadly to bees, even in very small amounts. Therefore, take caution when using them in garden areas or other places frequented by bees.

The main difference between these two insecticides is that permethrin is a synthetic chemical made in laboratories while pyrethrum is a completely natural substance acquired from chrysanthemums.

The effects of both pesticides are quite similar, but, as permethrin is synthetic, it is more stable and effective when exposed to sunlight. For this reason, synthetic permethrin is used in agriculture more often than pyrethrum to protect crops from unwanted insects. Farmers need more stable pesticides which can withstand exposure to sunlight on those sunny, hot summer days.

Both pyrethrum and permethrin have low toxicity to mammals and birds. However, cats can be particularly sensitive to them due to their inability to quickly break them down.

Altogether, the main difference between permethrin and pyrethrum is the way they are produced. One comes from flowers while the other is synthetically manufactured in laboratories and persists longer in the environment.

36 Comments

Rebecca

Thank you. I really appreciate your insight.

david minner

I am a trained agronomist and the information presented with this easy to understand message, especially as it relates to people, pet, and beneficial insects, is very very helpful in making decisions. Thank you.

linda harris

Hello, I haven’t been able to find a commercially made but non-toxic spray for roaches. I used to get one labeled as such, which had only pyrethrum I believe, as a main ingredient.

Are you able to make suggestions? I am looking for a spray to use occasionally to drive them from crevices where they run to hide, etc. I find that peppermint oil mixed with water doesn’t bring them out of hiding, and I don’t think it kills them.

    Karen

    Please check out our best cockroach sprays article because among the roach sprays listed in this article there are a few that are natural, non-toxic yet also very efficient at driving the roaches away.

Tyler

How is using thousands of acres of farmland to grow something we can make in a laboratory more eco-friendly? Considering most the two main types of chrysanthemum flowers used for this are grown in Africa, maybe they could be growing food crops instead.

Also, please stop telling your readers to spray for cockroaches unless their goal is to spread them around. Bait is the preferred option for German roaches.

    Insectcop

    Hi! We appreciate you seeking out to us and caring about the environment so much, however, I would like to point out that there is a major difference between ”being eco-friendly” and ”solving world hunger”. For something to be called ”eco-friendly”, it should cause no harm to the environment (pollution, etc).
    As for cockroaches, we prefer to give our readers intel on various methods that can be used, so they can make their own decision on which one works best for them. As a matter of fact, we actually have an article about these methods, where your suggestion has also been included.

    John S

    For many African farmers, py is a much more profitable crop than any food crops they may grow and is far more resilient to adverse weather. Py also breaks down very quickly, that is why it is preferred for applying indoors where humans gather and in kitchens.

Isabel

Thank you so much for the information.

lee

what should I use for ground yellow jacket

    InsectCop

    We suggest giving Hot Shot a try.

    Carie

    Hello. I want to kill ticks in the yard, but need it to be safe for birds, bees and my indoor/outdoor cats. Can I use pyrethrum?

    Kristiana Kripena

    If you can’t guarantee that pyrethrum has fully dried when bees, birds, and animals visit your backyard I’d stay clear of it. I’d recommend you to check out our article on flea and tick yard sprays where you should be able to find a suitable product for your needs.

Leslie Alexander

Hi, can use suggest an indoor spray to eradicate a weevil infestation, not only in the kitchen, but in the couch and upstairs bedroom/bathroom? Is Sawyers Permethrin safe to spray, right before bedtime, and not hurt myself or small dog?

    InsectCop

    Hello! Permethrin can be used on weevils, however, I would suggest trying some other methods before. The thing about weevils is that they can sometimes be difficult to fight with pesticides. If the infestation hasn’t gotten too severe, you can try removing them manually (e.g. by using a vacuum).

Vikki

What is best to use on lawn to eradicate chiggers & not be harmful to humans?
Is there a SAFE spray (cream/powder) to apply to skin or clothing before working in yard to prevent chigger bites?

    InsectCop

    There are a few things you could possibly do try. For example, you can try spraying our clothes with white distilled vinegar or food-grade Diatomaceous Earth. DE can also be used on the lawn itself ( 5 pounds pear 1000 sq.ft should do the trick). Also, keep the lawn well-groomed since they do love hanging in out in tall grass.

Darlene Aguillard

Hi! Having a terrible black fly (black fly/buffalo fly/gnat) outbreak here in the south that is actually killing off whole flocks of chickens – wondering the difference in Pyrethrum and Permethrin and if one is safer than the other to use on backyard poultry – on the birds themselves, the lawn, and/or the coop areas. I don’t want to harm bees that are in my yard. I read that spraying Pyrethrum at dawn or dusk when bees aren’t active would be the best course to take because while it can hurt bees when wet, it’s not harmful when dry. Wondering if you concur with that, and if that is the case, would it also not be effective at ‘harming’ the gnats once it dries? Any suggestions would be appreciated!

    InsectCop

    One of them is natural, coming from a flower, while the other one is manufactured synthetically, also being effective for a longer period of time. To be completely honest, we suggest using products that won’t harm pollinators, if possible. Even though there are precautions that can be taken to make the application safer to bees (such as spraying while bees are in their hives, perhaps putting a cloth over the flowers until the product dries, etc), the product still poses potential harm to the bees. One of our newest favourite is Mama Nature’s Mosquito Juice, which we recently reviewed. It’s natural, safe for pollinators, and will help you get rid of gnats as well! You should give the review a read! Good luck!

Babatunde

Thank you for your Intel
Can permethrin be sprayed directly into the chicken body

    Kristiana Kripena

    Permethrin is approved for use in poultry housing, and you can also apply permethrin powder to a chicken’s body. However, make sure that it doesn’t get into the chicken’s eyes or mouth. And always make sure to read the label of any product you’re using and follow all the instructions and precautions, especially, when it comes to using insecticides since some of them are highly toxic to cats, fish, and bees.

kris

We have a huge Tick problem in our woods at the house– we are just trying to clear some walk ways and we are getting 6 ticks a day on us–its Hot 90-95 deg and Humid so we have to wear shorts and t shirts.
I want to use a spray on my skin rather than spraying the vegetation and risking my dog eating the grass or harming any wildlife– what can I spray on myself?? my skin?

    Kristiana Kripena

    The most efficient tick repellents will be ones containing DEET or picaridin. There are some natural alternatives but those aren’t nearly as efficient as repellents containing DEET or other tick-repelling ingredients. You can also try using a natural tick yard spray that will keep the ticks away but that is also completely harmless to dogs and humans alike. You can find some good options in this article on the best tick yard sprays.

    Cheryl

    Can you tell me the best way to get rid of bed bugs. Permethrin or pyrethrum. Or any other tips

    Kristiana Kripena

    For best ways to combat bed bugs I encourage you to check out our article on how to get rid of bed bugs.

Mellenshire

Suggestions for swarming gnats? We recently purchased a new home in a hickory forest community. We have removed all the piles of old grass clipping from previous owners but we can’t even enjoy being outside due to gnats.

    InsectCop

    One option would be introducing their natural predators to the area. This would be the best option, as it would be a solution in the long term, as well as let you avoid using insecticides. If that’s not an option, you should think about looking into some more chemical solutions.

Vic

What tick repellant, permethrin or pyrethrin (or pyrethroids?), are commercially used in clothing for people who work in tick-infested areas? And how long do these chemicals last in the clothing (especially if the clothes are washed after each close encounter venture outdoors)

    InsectCop

    Not sure about whether that’s the option used in commercial environments, but is known permethrin to be efficient in controlling ticks. As for how long it lasts, we suggest checking the label of the specific product you’re going to use. Some products, like Sawyer Permethrin Spray, the claim to be efficient for six washings. The best way to know is by checking what the manufacturer says.

Maxine Neale

Please can you tell me if either of these 2 products can be used to spray on indoor clothing to kill moth larvae?

SHARON de Gaspé Power

This year we have had an infestation of rose chafer (Macrodactylus). They have devoured clematis, roses, peonies, cabbage and wisteria. They even munched on my marigolds that surrounded tomato plants. There were thousands that I discovered in my Goat’s Beard hedge. For this latter blight, I sprayed a product that had 0.25% permethrin content. The following morning, they were all gone. If one covers plants that have just been sprayed with a cheesecloth, how long would this be necessary to protect the bees. Also, does one have to repeat the spraying following a rainfall or upon contact with the spray, do the Rose chafers die within minutes. Thank you.

    InsectCop

    Permethrin should still be fine after the rain, assuming it had dried completely before the rain came. It might dilute it, though, so you might need to re-apply sooner. As for how long the treated areas should be shielded for, you should keep it up until the area has dried completely.

Sidney

What can i use to control mosquitoes both outdoors and indoors for a long term given the fact we have a large forest at the back of our neighborhood?

    InsectCop

    You should take a look at our article about getting rid of mosquitoes to see what your options are in general.

Elaine Woodriff

What is a good insecticide for follicle mites, please? I have been using a product containing pyrethrum, but it is not working to get rid of them. I have a bad infestation of follicle mites: in my eyebrows, inside my nose, ears, hair, and they have buried themselves under the skin on the back of my neck. They cause stinging itches and intense itching.

    InsectCop

    We suggest seeing a doctor, to perhaps give you a prescription.

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