As if carfentanil wasn't enough, a substance called 'acryl fentanyl' showed up from the labs in China and hit city streets. Over the last year, more and more artificially created, synthetic analogues of fentanyl made their way in to the United States drug supply and have already caused major overdose events. The fact of the matter is, there really isn't a lot of heroin around anymore. Most addicts who proclaim themselves to be heroin addicts are, in actuality, fentanyl addicts. As the opioid problem has pushed forward and evolved, heroin itself has become less of a problem, with fentanyl having the main spotlight. Unfortunately, instead of getting better, the drug problem has worsened with other things to fear than just tainted dope.

EMCDDA - Europol Joint Report 2017:

Acryloylfentanyl is a synthetic opioid. It is closely related to fentanyl

Acryloylfentanyl has been available in the European Union since at least April 2016 and has been detected in 6 Member States. In most cases it has been seized as a liquid, but other forms such as tablets, powders and a capsule have also been detected. The detected quantities are relatively small; however, they should be taken in the context of the high potency of the substance

Excerpt from http://www.emcdda.europa.eu/system/files/publications/3873/TI_PUBPDF_TDAS17001ENN_PDFWEB_20170221105322.pdf

Acrylfentanyl

Duration: A rare opioid and fentanyl analogue (not to be confused with acetyl-fentanyl), this drug is a powerful and potent analgesic. Little reliable information exists, even for basic usage such as dosage. Exercise extreme caution. Overdose may result in respiratory depression. Do not mix with depressants or stimulants. Potentially neurotoxic and carcinogenic. Note: Please exercise extreme caution with this substance.
Route	Onset	Duration	After Effects
Tripsit Factsheets
Acrylfentanyl Basic Information: http://drugs.tripsit.me/acryl-fentanyl
All ROAs:	10-45 minutes	3-5 hours	1-16 hours
Effects: Euphoria, Dry Mouth, Mood lift, Itchiness, Relaxant, Constipation, Pupil constriction, Analgesia.

World Health Organization 2017:
First described in 1981, acryloylfentanyl is an analogue of fentanyl(a scheduled opioid in the 1961 Single Convention)that in the last few years has appeared on drug websites selling "research chemicals",predominantly in nasal spray solutions or powder form often as an alternative to illicit opioids.In non-clinical laboratory studies, it has been shown to be an opioid receptor agonist and a potent and long-lasting analgesic agent but has no known or recorded therapeutic use.

Acryloylfentanyl is being used and abused for non-medical purposes in the same setting and for the same desired effects as other opioids. Reported adverse effects (including intoxication) include miosis, decreased consciousness and respiratory depression.Fatalities have been reported in Europe and the United States, occurring within a relatively short time period.

The potency of the drug also poses health risks to those coming into contact with any material, which includes the general public as well as medical, forensic and law enforcement personnel.

Whilst there are no animal or human studies that have investigated the abuse and dependence potential of acryloylfentanyl, the information available demonstrates acryloylfentanyl is liable to similar abuse and productive of similar ill effects as fentanyl and other fentanyl analogues

Excerpt (PDF 21 pages): https://www.who.int/medicines/access/controlled-substances/CriticalReview_Acrylolyfentanyl.pdf?ua=1

• A highly potent opioid analgesic
• An analog of fentanyl
• Slightly more potent than fentanyl itself and has a longer duration of action
• Has been sold online as a designer drug

Acrylfentanyl has been linked to 20 deaths in Sweden as well as two deaths in Denmark in summer 2016