# Synthetic opioid carfentanil **URL:** \ **Category:** Factual Questions\ **Created:** [October 16, 2025, 6:46pm UTC](https://boards.straightdope.com/t/synthetic-opioid-carfentanil/1024027 "2025-10-16T18:46:13Z")\ **Posts on this page:** 14\ **Page:** 2
**Author:** ![Qadgop\_the\_Mercotan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/qadgop_the_mercotan/32/83_2.png) [@Qadgop\_the\_Mercotan](https://boards.straightdope.com/u/Qadgop_the_Mercotan)\ **Post date:** [October 17, 2025, 9:54pm UTC](https://boards.straightdope.com/t/synthetic-opioid-carfentanil/1024027/21 "2025-10-17T21:54:08Z")
Oh, I’m sure that can be done and given safely to patients in a controlled medical setting, but there’s no real advantage to it, since fentanyl and other opioids do the job equally well. But the problem arises when the legit stuff gets diverted into the addict arena where they won’t draw up precise doses, they’ll snort or IV whatever much THEY think will get them high enough, and more of them will end up dead. Even more than with fentanyl, potentially. At least that’s what I conclude, based on past readings of the FDA and DEA papers on whys and wherefores of Schedule I & II drug regulation ---
**Author:** ![Jackmannii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jackmannii/32/311_2.png) [@Jackmannii](https://boards.straightdope.com/u/Jackmannii)\ **Post date:** [October 18, 2025, 4:44am UTC](https://boards.straightdope.com/t/synthetic-opioid-carfentanil/1024027/22 "2025-10-18T04:44:11Z")
It seems that avoiding error in preparing pharmaceutical dilutions isn’t all that simple. > **[How Accurate are Your Dilutions?](https://www.pharmtech.com/view/how-accurate-are-your-dilutions)** > > The choice of dilution schemes can minimize solution preparation errors. The margin for error also diminishes considerably when dealing with a far more powerful drug. > [@](#): > > Even homeopaths know how to do that. One wonders just how accurate homeopathic dilutions are. Though the practical import of screwing up is probably nil (“Did I let a single molecule of “active” substance slip into the final product? Oh nooooooooo!”) \*I’m guessing that mouth pipetting is not a good idea when preparing a solution of carfentanil. ---
**Author:** ![nearwildheaven](https://avatars.discourse-cdn.com/v4/letter/n/90db22/32.png) [@nearwildheaven](https://boards.straightdope.com/u/nearwildheaven)\ **Post date:** [October 18, 2025, 6:05am UTC](https://boards.straightdope.com/t/synthetic-opioid-carfentanil/1024027/23 "2025-10-18T06:05:54Z")
Assuming you could even get the real thing in the first place, you would probably die, unless you got only the microscopic dose that would work for a person. It’s a large animal tranquilizer, used mainly for megafauna like elephants and hippos, and is only available under very limited protocols, at least here in the States. I’m very aware that it’s shown up on the American black market. 30+ years ago when I was in pharmacy school, it was mentioned just so we would know it existed. I never heard of it again until the past few years. ---
**Author:** ![nearwildheaven](https://avatars.discourse-cdn.com/v4/letter/n/90db22/32.png) [@nearwildheaven](https://boards.straightdope.com/u/nearwildheaven)\ **Post date:** [October 18, 2025, 6:09am UTC](https://boards.straightdope.com/t/synthetic-opioid-carfentanil/1024027/24 "2025-10-18T06:09:04Z")
It may also be placed into some kind of solution, or more likely an emulsion, that would make it release slowly into the animal’s body. ---
**Author:** ![Francis\_Vaughan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/francis_vaughan/32/3093_2.png) [@Francis\_Vaughan](https://boards.straightdope.com/u/Francis_Vaughan)\ **Post date:** [October 18, 2025, 12:41pm UTC](https://boards.straightdope.com/t/synthetic-opioid-carfentanil/1024027/25 "2025-10-18T12:41:15Z")
I’m curious. Given the ridiculous potency, where even a large animal felling dose is units of milligrams, why not just use fentanyl to drop a beast? The potency of carfentanil would seem to be unnecessary, and just causes grief. It seems to be a drug with no useful justification or purpose. Perhaps the difficulty in handling is a deterrent to someone trying to divert those animal doses to nefarious channels. The manner in which fentanyl has become such a serious problem is not to be taken lightly. But as noted above, the drug trade is not something known for its duty of care. ---
**Author:** ![puzzlegal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/puzzlegal/32/3827_2.png) [@puzzlegal](https://boards.straightdope.com/u/puzzlegal)\ **Post date:** [October 18, 2025, 12:54pm UTC](https://boards.straightdope.com/t/synthetic-opioid-carfentanil/1024027/26 "2025-10-18T12:54:10Z")
My understanding is that fentanyl is used in surgery because it is both fast to act and also fast to be cleared out of the body. This makes it a good fit for use in surgery, where you want to prep the patient quickly and you also want the patient to recover quickly. But that “quick recovery” might not be ideal for handling megafauna. I didn’t know what the dynamics are of carfentanyl, but it’s a different drug, they may be different from those of fentanyl. ---
**Author:** ![Francis\_Vaughan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/francis_vaughan/32/3093_2.png) [@Francis\_Vaughan](https://boards.straightdope.com/u/Francis_Vaughan)\ **Post date:** [October 18, 2025, 1:03pm UTC](https://boards.straightdope.com/t/synthetic-opioid-carfentanil/1024027/27 "2025-10-18T13:03:51Z")
> [@puzzlegal](#): > > But that “quick recovery” might not be ideal for handling megafauna Yes, that is a good point. Noted earlier, carfentanil binds strongly to the receptors, so that is an important difference. ---
**Author:** ![Marvin\_the\_Martian](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/marvin_the_martian/32/2898_2.png) [@Marvin\_the\_Martian](https://boards.straightdope.com/u/Marvin_the_Martian)\ **Post date:** [October 18, 2025, 4:39pm UTC](https://boards.straightdope.com/t/synthetic-opioid-carfentanil/1024027/28 "2025-10-18T16:39:46Z")
Apparently Carfentanil was pulled from veterinary use in 2016 in favor of the slightly less potent Thiafentanil and the much older etorphine: > **[The Use of Ultrapotent Opioids in Veterinary Medicine](https://asra.com/news-publications/asra-newsletter/newsletter-item/asra-news/2021/02/01/the-use-of-ultrapotent-opioids-in-veterinary-medicine)** ---
**Author:** ![nearwildheaven](https://avatars.discourse-cdn.com/v4/letter/n/90db22/32.png) [@nearwildheaven](https://boards.straightdope.com/u/nearwildheaven)\ **Post date:** [October 18, 2025, 7:28pm UTC](https://boards.straightdope.com/t/synthetic-opioid-carfentanil/1024027/29 "2025-10-18T19:28:19Z")
Carfentanil is probably faster-acting, and shorter-acting, and also requires less fluid to deliver the dose. ---
**Author:** ![Dissonance](https://avatars.discourse-cdn.com/v4/letter/d/85f322/32.png) [@Dissonance](https://boards.straightdope.com/u/Dissonance)\ **Post date:** [October 18, 2025, 7:41pm UTC](https://boards.straightdope.com/t/synthetic-opioid-carfentanil/1024027/30 "2025-10-18T19:41:16Z")
> [@Jackmannii](#): > > There was an incident in Russia where numerous deaths resulted when aerosolized (weaponized) carfentanil was used against terrorists. If anything, ‘numerous’ is an understatement. It killed 132 of the 912 hostages. [Moscow theater hostage crisis - Wikipedia](https://en.wikipedia.org/wiki/Moscow_theater_hostage_crisis) ---
**Author:** ![nearwildheaven](https://avatars.discourse-cdn.com/v4/letter/n/90db22/32.png) [@nearwildheaven](https://boards.straightdope.com/u/nearwildheaven)\ **Post date:** [October 21, 2025, 9:53pm UTC](https://boards.straightdope.com/t/synthetic-opioid-carfentanil/1024027/31 "2025-10-21T21:53:46Z")
That they used carfentanil may actually make sense. I’ve always known that fentanyl itself would not do that to people, when used that way. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [October 21, 2025, 10:06pm UTC](https://boards.straightdope.com/t/synthetic-opioid-carfentanil/1024027/32 "2025-10-21T22:06:24Z")
The problem of course being the rather fine line between a prompt knockout dose and a fatal dose. A little thought would readily suggest that any sort of dispersal munition deployed in a large single-room building would be the opposite of uniform minimum effective dosing. Instead some people, hostage or terrorist, got 20x lethal doses and others got nothing. Which left the unaffected terrorists free to a) slaughter the remaining hostages, and b) fight effectively against the assaulting police troops. As Patton said of a different battle, “It was a shambles.” ---
**Author:** ![nearwildheaven](https://avatars.discourse-cdn.com/v4/letter/n/90db22/32.png) [@nearwildheaven](https://boards.straightdope.com/u/nearwildheaven)\ **Post date:** [October 21, 2025, 10:45pm UTC](https://boards.straightdope.com/t/synthetic-opioid-carfentanil/1024027/33 "2025-10-21T22:45:02Z")
I guess this could have been used in smaller quantities than an anesthetic gas. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [October 21, 2025, 11:53pm UTC](https://boards.straightdope.com/t/synthetic-opioid-carfentanil/1024027/34 "2025-10-21T23:53:29Z")
The thinking of using a very strong and fast acting material to prevent the bad guys from enacting a suicide pact w the hostages makes a lot of sense as a tactical _idea_. The problem is in the _implementation_, where the fantasy of even effective dosing crashes into the ugly reality of how dispersing munitions really work. [Previous page](https://boards.straightdope.com/t/synthetic-opioid-carfentanil/1024027.md?page=1)