Well, neem oil works against bed bugs, but it's not a miracle solution. On this page you can learn how to get rid of bed bugs for good...
I get many questions about bed bug control with neem oil:
Depending on how you ask the question the answer is yes and no.
So, with that said: Neem oil can help prevent bed bug bites.
Neem oil can kill bed bugs if you can get it on them, but unfortunately that's irrelevant if you are dealing with an infestation...
Neem oil will not control a bed bug infestation. In fact, you have no hope of eradicating an infestation by just spraying, no matter what you spray.
The problem with bed bugs is that they don't live on you, they can live anywhere. They are so flat, they get into the tiniest cracks, and that's where they shelter during the day. They only come out at night.
Also, bed bugs can live a year or longer without blood! They don't need to come out of their hiding spots if they don't want to.
Neem oil could kill bed bugs, but neem is also a bed bug repellent. You can't reach the bed bugs with your neem oil spray and they will make sure they stay away from it.
Neem's insecticidal action only lasts for a week or so. So the bed bugs just stay deep down in their hiding places until it's safe to come out again.
Unfortunately the same is true for pretty much any other spray. If it is a repellent as well, and many insecticides are, it won't be effective. It won't work unless you get the stuff on every single bed bug and nymph and egg and that is of course impossible.
To control bed bugs you need a substance that's either so horribly toxic that it kills everything in the vicinity instantly, even if that anything is trying to hide and shelter somewhere. Or you need something with lasting insecticidal properties that does not repel. But even then you often find the critters are already resistant to it.
Also, an insecticide that does not break down quickly is obviously more harmful to yourself and your family... What to do?
If I was dealing with bed bugs and wanted to avoid chemical toxins, I'd use diatomaceous earth.
Diatomaceous earth is a totally non toxic powder. (Really. They even put it in pet food to keep it fresh)
The powder kills insects because it is abrasive on a microscopic level. It scratches and damages their chitin skin and they dry out and die. It's a mechanical action that they can't get resistant to and it lasts forever.
But using diatomaceous earth alone will not be enough. (Neither would be using any insecticide.) Eradicating bed bugs means major warfare.
If you want to learn more about eradicating bed bugs, the best document I know of is available here for free download:
Just right click on the cover of the book and save it to your hard drive.
Even though this guide was written for chemical warfare you can learn a lot from it. You don't need to read all of it, but the chapter that describes how to exactly go about a bed bug eradication is enlightening. All the preparation before you even get to the stage where you would apply the insecticide...
So, cleaning comes first. I can not overemphasize just how thorough you need to be with all the cleaning, vacuuming, steaming etc. Always make sure you don't blow or disperse the bugs instead of containing them... The mattress needs to be totally sealed with a special cover or thrown out.
Once you have cleaned everything, apply the diatomaceous earth along the corners, carpet straight edges, mattress seems, anywhere that bed bugs may hide or have to walk through to get to you.
And then you can use neem oil products on yourself as an additional protection. And, once you are sure the current infestation is really eradicated for good, use neem sprays or leaf dust in the rooms to prevent future infestations.
Neem products containing neem extracts are great to use on the skin to soothe and heal it while suffering from bed bug bites. And they will help prevent getting bitten.
But it will be a long battle to fully eradicate the bed bugs with neem oil...