MDPHP is a stimulant in the cathinone and pyrovalerone classes, making it structurally similar to α-PVP, α-PHP, and MDPV. It has a very limited history of use, having shown up primarily in Europe in the mid-2010s. There’s reason to believe the purity and content of MDPHP batches has been highly variable, sometimes involving other cathinones being sold as it, which makes it harder to characterize its effects.

A lot of the attention on the drug has come from the media. Reports of people using “monkey dust” (said to either be MDPHP or MDPV) and then becoming violent, psychotic, or suicidal have spread around the UK and Australia in particular. Claims suggesting it has a high chance of making people psychotic or violent are largely baseless. Stimulant psychosis is possible with high doses, prolonged use, and/or sleep deprivation, but it is not the typical effect nor is it unique to MDPHP; it can also easily happen when abusing common stimulants like cocaine or methamphetamine. With reasonable doses and sleep, psychosis is very unlikely.

MDPHP = 3′,4′-Methylenedioxy-α-pyrrolidinohexiophenone; “monkey dust”

PubChem: 119057580

Molecular formula: C17H23NO3

Molecular weight:  289.375 g/mol

IUPAC: 1-(1,3-benzodioxol-5-yl)-2-pyrrolidin-1-ylhexan-1-one


Oral (tentative)

  • Light: 10 – 20 mg
  • Common: 20 – 40 mg
  • Strong: 40+ mg

Inhalation (tentative)

  • Light: 5 – 10 mg
  • Common: 10 – 20 mg
  • Strong: 20+ mg

Intranasal (tentative)

  • Light: 5 – 10 mg
  • Common: 10 – 20 mg
  • Strong: 20+ mg

Some users have reported the common dose is upwards of 100 mg, but those reports are cause for skepticism. Since the majority of reports indicate the drug is much more potent than that, and therefore using 100 mg at once may be an overdose, it seems possible the experience reports using higher doses were due to purity issues or other stimulants being sold as MDPHP.

Only light or common doses should be taken. Then, based on the effects, the dose can be carefully adjusted. It’s best to only redose every few hours in order to avoid unexpected potentiation of your earlier doses, which could cause overstimulation and various negative effects.

Some users report common doses, especially when used orally, are pretty good for productivity and focus, while the other routes are superior for recreation.

Inhalation is a very common ROA for this drug, but reports indicate MDPHP must be carefully heated to avoid decomposing the substance. Decomposition leaves a dark-colored unusable residue. It’s also widely described as having an unpleasant taste that can occasionally trigger nausea.



  • Total: 3 – 6 hours
  • Onset: 00:30 – 00:60


  • Total: 2 -4 hours
  • Onset: 00:05 – 00:10


  • Total: 2 – 4 hours
  • Onset: 00:05 – 00:15

It’s a short-lasting drug that often loses its euphoria/mood enhancement within an hour or two, regardless of ROA. The final couple hours of the main effect period are less uplifting, but still strongly stimulating. How comfortable that state is depends on the user and the specific experience: sometimes the latter half of the effect period is still useful and sociable, motivational, etc, but some people begin to experience a fast decline in mood that encourages redosing.

After the main effect period there’s usually at least a couple hours of residual stimulation that will cause insomnia, but it doesn’t take very long for sleep to become possible (if you’ve taken common doses). During the residual stimulation period users are often in a pretty neutral mood and have little to none of the motivation boost that was present during the main effect period.

Experience Reports




  • Stimulation
  • Increased motivation
  • Mood enhancement and euphoria
  • Increased sociability
  • Increased confidence
  • Relatively smooth feeling
  • Sexual enhancement (e.g. greater interest in sex)


  • Anxiety
  • Paranoia
  • Dry mouth
  • Uncomfortable physical stimulation
  • Muscle tension
  • Increased blood pressure (BP) and heart rate (HR)
  • Compulsive redosing
  • Restlessness

The relative lack of experience reports (at least in English; more reports exist in Polish and other languages) combined with people likely receiving batches of variable potency and composition has made it difficult to characterize the substance. Typically it’s said to be less intense than α-PVP and MDPV, while being somewhat comparable to α-PHP, though users tend to prefer one or the other. While it’s less intense, that can be a positive characteristic, so which drug people prefer depends on what they’re trying to get from the experience. If you’re seeking the greatest euphoria and rush, MDPHP is likely inferior, but it can be superior if you want a more relaxed/mellow experience with a shorter duration. Usually it’s more mood enhancing than substances like amphetamine, 3-FPM, and 2-FMA.

MDPHP is sometimes preferred to α-PVP and MDPV because it has a lower risk of psychosis, sleep issues, drawn out compulsive redosing, and scatterbrained effects. Given it’s less likely to cause those issues than some of the other cathinones, it’s even sillier that it has received so much media attention.

There’s a nearly equal number of English language reports saying it’s a worthwhile drug or saying it’s not that effective and doesn’t offer enough mood enhancement to justify using it. One of the factors in this discrepancy (a discrepancy that’s greater than average) are the aforementioned purity/misrepresentation issues. The Polish language and other European experience reports are said to be more positive, which could be explained by more reliable purity in those regions. Note: TDC has not been able to verify the contents of those non-English experience reports.


A lot of the cathinones and other RC stimulants produce a stimulated but scatterbrained state. At common doses MDPHP seems to preserve cognition comparatively well, so it can be used for productive purposes. That preservation of cognition when coupled with increased motivation and task enjoyment can make it pretty useful.

Other psychological effects include general mood elevation, a greater desire to socialize, and a greater interest in sex.

Compulsive redosing

While seemingly less compulsive than α-PHP and MDPV, users can still get stuck in a loop of chasing progressively shorter-lasting euphoria and avoiding the comedown. This sometimes leads to sleep deprivation due to binging, which is a very bad idea. If you have any self-control issues when it comes to stimulants it’s best to avoid using MDPHP. Alternatively, you should at least strictly plan out how you’ll use it rather than making decisions in the heat of the moment.

Some users report it’s compulsive despite not being euphoric, which is also seen with other stimulants. People can mindlessly get trapped in a cycle of use due to the short-lasting positives each dose provides and because the comedown is so undesirable.


Increased heart rate and blood pressure are common, but those changes normally don’t cause any distress. The physical sensations that can be problematic include muscle tension, e.g. in the legs or around your chest; a couple users have reported feeling like their trunk was being significantly constricted. Shortness of breath can occur with or without the muscle tension effects, though both the chest constriction and labored breathing effects are uncommon.

After effects

At common doses it causes less insomnia than a lot of stimulants, so users frequently report being able to sleep 6-8 hours after dosing. The comedown is typically less severe than the comedown from more euphoric and compulsive cathinones, but it can still easily include agitation, low mood, reduced productivity, and physical discomfort (e.g. aches and tension). Even people who really like it often say the best effects last just a couple hours and they’re followed by boring and/or uncomfortable mental and physical stimulation.

The comedown is worse in a dose-dependent way. The more you use, both in terms of total dosage and the number of redoses, the more likely you are to have an uncomfortable comedown and difficulty sleeping.


MDPHP is a cathinone and more specifically a pyrovalerone. This means the molecule has a core amphetamine structure with a β-keto substitution (making it a cathinone) and it has a pyrrolidine ring substitution at its nitrogen atom (making it a pyrovalerone). From there, MDPHP includes a 3′,4′-methylenedioxy group, similar to MDPV and MDMA. That group is the only difference between MDPHP and α-PHP.

There’s a small amount of evidence demonstrating alleged “MDPHP” batches are actually other substances or a combination of drugs. This is not surprising considering the nature of the cathinone market, which often sources from Chinese manufacturers of questionable reliability. A sample sent to EcstasyData was shown to contain a different cathinone, 3′,4′-Methylenedioxy-N-tert-butylcathinone (MDPT), and the differences between batches that are described by users indicate purity issues and misrepresentation are common.


No formal pharmacological studies have been conducted, so the drug’s mode of action can only be theorized based on its subjective effects and its similarity to other cathinones/pyrovalerones that have been studied. It probably functions at least as a reuptake inhibitor for dopamine and norepinephrine, and some reports claim a serotonergic component could also be present. Direct binding at receptors, intracellular activity, and other potential effects have not been evaluated.


The drug appears to have been synthesized around 1960, but it wasn’t until the mid-2010s that use began. It’s been sold through the research chemical market and has often been used as an alternative to popular RC cathinones like α-PVP and MDPV. It is more popular in some European countries (e.g. Poland) than in North America.

The EMCDDA was first notified about the drug in 2014, with a case in Sweden (Gaspar, 2015). Sweden’s STRIDA project investigated cases with analytically confirmed pyrovalerone use between 2011 and 2016. In total there were 114 intoxicated patients and the most common drug was α-PBP (n=43), followed by MDPHP (n=26) (Beck, 2017).

Sensationalist media reports first appeared in the UK in 2018 and then in Australia by early 2019. Major news providers like the BBC have suggested the drug is commonly associated with violent behavior (e.g. claims about cathinones causing cannibalism) and suicide, but there is very little evidence to support this.

According to the news stories (which often implicate MDPV even though MDPHP appears to be the real causal drug), a relatively cheap substance called “monkey dust” saw widespread use in the north of the UK beginning in 2018. Paramedics and police have described cases where people allegedly used a cathinone and then tried to commit suicide, became generally psychotic, or gained “superhuman strength” that made them very difficult to control. These reports are nearly identical to those from earlier rounds of the cathinone hysteria, such as reports about MDPV and α-PVP (flakka) that claimed the drug was nearly causing an epidemic and police were struggling to control users.

Most likely there are some instances where someone is acutely mentally ill in association with a cathinone and becomes a danger to themselves or others. This is known as stimulant psychosis (or in some instances a similar condition called excited delirium) and it is best handled with medical attention and psychological support, such as reassurance. As of 2019 there’s effectively no evidence that MDPHP is causing major societal problems. Unfortunately reality is contradicted by statements from emergency medical service providers and police who describe terrifying instances of “zombie”-like people and absolutely insane individuals. Some of those cases probably exist, but we don’t have evidence that toxicology testing has frequently shown MDPHP to be the cause. One of the widely shared incidents allegedly involving MDPHP or MDPV, in which a man climbed on a roof and jumped down onto a car, turned out to be four years old and was not confirmed to be drug-related, reports Max Daly at Vice.

Police in Staffordshire, UK said in August 2018 that they had dealt with 950 cases related to “monkey dust” in the past three months, giving an average of 10 cases per day. In early 2019 Buzzfeed covered the topic and reported there was an Australian case in which a woman used “monkey dust” and “ended up licking the dance floor so feverishly her tongue bled.” Other incidents cited by Buzzfeed include users running into traffic, injuring themselves, and jumping off buildings. Most of these cases have not been confirmed to have involved either drug, yet they’ve been described as drug-related in articles.

Legality (as of February 2019)

Australia: Not specifically controlled but might be an illicit analog.

Canada: Not specifically controlled but may be an illicit analog.

UK: Class B

US: Unscheduled; Covered by Federal Analog Act


Very little is known about MDPHP, so we must extrapolate from similar stimulants. Overdoses could easily cause excessively high heart rate and blood pressure, confusion, hallucinations, paranoia, and anxiety. The psychological and cognitive negatives are significantly increased with prolonged use from multiple doses and from sleep deprivation. Binging on the drug is very risky. Although violent reactions aren’t the usual outcome of mild to moderate stimulant psychosis, it’s still an inherently dangerous state to be in. Stimulants should never be used in place of sleep. Nearly all of the severe experiences reported by users involve prolonged use for upwards of 1-2 days in the context of little to no sleep.

Acutely an overdose can be physically dangerous due to its cardiovascular impact and increased risk of seizure. Cardiovascular complications like myocardial infarction and stroke are possible, though no case reports describing MDPHP overdoses in a medical setting have been published.

Beck (2017) reported case details from 26 people confirmed to have used MDPHP and found it was associated with effects like thorax pain, labored breathing, panic, dizziness, psychosis, aggressiveness requiring police assistance, hypertension, blurry vision, and cold extremities. This was with serum concentrations ranging from 1.0 to 14.3 ng/mL and urine concentrations of 19 to 48 ng/mL.

The long-term effects are simply unknown. Because there is so little information about its effects it would ideally be avoided entirely. If it is used, it should only be taken infrequently and at common doses.


No fatalities have been reported as of February 2019, although there is every reason to believe fatal toxicity is possible when overdosed. Adamowicz (2018) reported a case of fetal death temporally linked to MDPHP and α-PHP use in a young female, though the exact cause of the asphyxia that killed the fetus was not determined.

(Adamowicz, 2018) – A fetal death associated with MDPHP and α-PHP.

  • 21-year-old female who was 36-weeks pregnant. She began feeling bad and vomited, then was found shortly thereafter unconscious. When EMS arrived 2 h later she was conscious with psychomotor agitation.
    • She’d been smoking tobacco and using alcohol during the pregnancy.
  • In ED: Psychomotor agitation, anxiety, and mumbled speech.
  • Vaginal spotting and apparent intrauterine fetal death were seen, so she was admitted to the ICU. Vitals of BP 160/90, HR 130, temp 36.8°C, and blood glucose 97 mg/dL.
  • Due to increased psychomotor agitation she was given diazepam, midazolam, and propofol. Intubation and respiratory support were ultimately supported.
  • Radiographic exam of her chest showed lung inflammation.
  • Toxicology (collected 1 h post-admission)
    • MDPHP
      • Mother
        • Blood: 16 n/mL
        • Urine: 697 ng/mL
      • Fetus
        • Blood: 76 ng/mL
    • α-PHP
      • Mother
        • Blood: traces
        • Urine: 136 ng/mL
      • Fetus
        • Blood: 12 ng/mL
    • No other drugs detected, including alcohol, common drugs, and nearly 200 NPS.
  • Medical examiner concluded the newborn was stillborn and the death was due to intrauterine asphyxia of unknown etiology.

Risky combinations (list is not exhaustive)

  • Any other stimulant (e.g. phenidates, amphetamines, cathinones)
  • Serotonergic antidepressants like SSRIs, SNRIs, and TCAs.
  • Psychedelics
  • Sedatives, e.g. benzodiazepines
    • This combination is helpful and quite safe when someone needs to sleep or if they’re experiencing anxiety or discomfort on a stimulant, but using sedatives concurrently with stimulants can mask the level of impairment you’re actually experiencing, making overdoses more likely. Planning out your doses before using is even more important if you anticipate using a sedative at some point. Making redose decisions while also on a sedative is a bad idea and fairly likely to result in using too much.


Adamowicz, P., & Hydzik, P. (2019). Fetal death associated with the use of 3,4-MDPHP and α-PHP. Clinical Toxicology, 57(2), 112–116.

Beck, O., Bäckberg, M., Signell, P., & Helander, A. (2018). Intoxications in the STRIDA project involving a panorama of psychostimulant pyrovalerone derivatives, MDPV copycats. Clinical Toxicology, 56(4), 256–263.

Gaspar, H., Bronze, S., Ciríaco, S., Queirós, C. R., Matias, A., Rodrigues, J., … Santos, S. (2015). 4F-PBP (4′-fluoro-α-pyrrolidinobutyrophenone), a new substance of abuse: Structural characterization and purity NMR profiling. Forensic Science International, 252, 168–176.

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