Stimulant drugs, or uppers - like crystal meth (Tina/Ice), speed/amphetamine, coke/cocaine, MDMA (ecstasy/molly) or mephedrone - can have euphoric and disinhibitory effects, and can make you more social (prosocial) and more horny and into sex (prosexual). In addition to increasing the user's physical and sexual stamina. For this reason, uppers are popular in chemsex and other communities where drugs other than alcohol are used specifically for sex.

This article takes a look at some of the most important effects and risks to bear in mind when (or ideally before) having sex on uppers.

Uppers not only have the ability to make you horny; they can also make your sexual urges more difficult to resist by reducing your inhibitions and impulse control, and they may even give rise to some urges or preferences that you otherwise would not have had.

Because of these effects, uppers can cause you to make decisions about sex that you might find yourself regretting later. Even if disinhibition and increased courage to explore new pleasures can be desirable and are valid reasons for using uppers for sex in the first place, the risk of overstepping your own boundaries is real and worth noting.

This risk can be mitigated, however, by establishing some ground rules with your partner(s) if the situation allows it. By agreeing on what you are comfortable with beforehand, you will be able to remind each other if you get too carried away later. By putting this agreement in writing, for instance when texting before a meetup, later disagreement is also avoided.

Note that frequent (i.e. near daily) use of meth is associated with elevated impulsivity even on the days when meth is not used. It is not known whether this is a causal effect of frequent meth use or a personality trait more common in those who tend to use meth frequently, but any causal effect could likely be avoided by not using meth (or other uppers) frequently.

Uppers impair our ability to recognize the emotional quality of other people's facial expressions. While alcohol tends to make us interpret facial expressions as more negative than they really are – leading to many lovers' quarrels and bar brawls – uppers tend to make us interpret facial expressions as less negative than they really are. This effect is typically seen when someone is under the influence of the drug, but people who develop psychosis from frequent use of uppers may also experience the effect when not under the influence.

Not being able to read facial expressions can obviously be a problem when attempting to initiate sex, as it becomes harder to pick up on signs that someone is not interested. It can also be a problem during sex, however, and especially so when both (or all) participants are under the influence, since one might not notice that someone is no longer consenting to and enjoying an act. This elevates the risk of experiencing, or committing, sexual assault.

(Some also experience reduced empathy when using certain uppers. If you know that you respond in this way, you should be open with your partners about this before having sex on these drugs.)

In chemsex, the issue of consent is particularly well known when it comes to the use of GHB/GBL, which is usually combined with an upper and can become strongly sedating once the upper's effect wears off.

Loss of the ability to consent can also present in less obvious ways, however, as in the case of drug-induced psychosis. This is not entirely uncommon in chemsex, especially if someone goes on a sleepless upper binge for more than 24 hours, or if someone uses uppers in high doses when they are already sleep deprived.

Someone experiencing a drug-induced psychosis from uppers may become paranoid, and their fear and confusion should be recognized and responded to quickly in order to prevent the situation from escalating.

If you are throwing an organized sex party, it is therefore a good idea to have a sober sitter who can assess the situation if needed. In an unorganized setting where everyone is under the influence, it is better to minimize the risk of someone experiencing psychosis by encouraging adequate sleep before and between sessions, as well as by educating first-timers. (If someone has a personal or family history of psychosis, they should be very cautious with uppers and perhaps use only GHB/GBL.)

In addition to increasing your physical and sexual stamina, uppers increase your heart rate and blood pressure. This means that having sex on uppers can place considerable strain on your heart and blood vessels if you are not in good physical shape and health.

This strain is not necessarily much greater than that of an intense workout, but since uppers elevate your threshold for pain and fatigue, the risk of physical overexertion becomes much greater, since you can push yourself much further than you normally would be able to.

If you have a heart condition, or if your age and fitness level put you at elevated cardiovascular health risk, you should pace yourself or take a break if you feel your heart racing when having sex on uppers. Also, bear in mind that coke is likely much worse for the heart than other uppers, and combining it or other uppers with alcohol may exacerbate arrhythmias (irregular heartbeat) and increase your risk of having a heart attack or stroke.

Uppers have analgesic effects that elevate your pain threshold and sensitivity. This makes "basic" safety precautions like using enough lube much more important when using uppers, since uppers might prevent you from noticing excess friction or skin tearing in the heat of the moment, increasing your risk of a sexually transmitted infection.

This becomes even more important if you are combining uppers with ketamine – which is technically also an upper in the cardiovascular sense, although its dissociative properties make it similar to a downer in some respects – since ketamine has very strong analgesic properties and is used specifically for this reason by some during fisting.

Uppers are hyperthermic, meaning they can elevate your body temperature and inhibit thermostatic regulation. This is especially true when uppers are used during physical activity, in high doses and/or in high ambient temperatures. For this reason, having physically intensive sex on uppers, especially in hot environments like saunas, can be dangerous.

In addition to being dangerous in itself if severe enough, hyperthermia can exacerbate the toxic effects of uppers on your internal organs. This is because the metabolites of the drug can cause free radicals to form, leading to oxidative stress, and the body's ability to counteract this with antioxidants becomes significantly impaired at higher temperatures.

For instance, MDMA, the active ingredient in molly and ecstasy, is not particularly toxic to human cells in moderate amounts, but an elevated body temperature may cause normally well-tolerated doses to have toxic effects on serotonin neurons in the brain. It can also lower the threshold dramatically for how much MDMA is needed to trigger a serious overdose, which can be fatal without immediate medical care. This risk is not trivial, since MDMA's hyperthermic effects are strong and can be amplified by alcohol, caffeine or other uppers.

While lethal overdoses are less common with other uppers, meth is considered more toxic to the brain than MDMA, so minding your body temperature is also wise when using meth. Also, avoiding hyperthermia can make the comedown and hangover much much more bearable, regardless of what type of upper is used.

The easiest way to avoid hyperthermia is to manage your dosage and the intensity of your physical activity, as well as to avoid mixing several uppers (including caffeine!) or uppers with alcohol.

If you do begin to overheat, it can be a good idea to take a cool (but not freezing!) shower, sit with bare skin by an open window (without falling out of it!), or soak a cloth in cold water and hold it against the veins on the side of your neck.

When things get hot and sweaty, it can be tempting to drink a lot to rehydrate and cool down. However, drinking large amounts of water when having sex on uppers can be quite dangerous due to the danger of hyponatremia caused by water poisoning.

This condition occurs when the body's sodium levels become too low relative to the water levels, and it can occur much more easily when you are using uppers, since many of them have strong antidiuretic properties that cause the body to get rid of salts (through sweating) more effectively than fluids, thereby causing an electrolyte imbalance.

Hyponatremia can be a serious and potentially life-threatening condition whose common symptoms may include nausea or vomiting, headache, confusion, lethargy, muscle weakness, fading in and out of consciousness, seizures and coma. Suspected cases of hyponatremia should be attended to by a medical professional. Do not just give salt to someone who already has many hyponatremic symptoms, as this can be unsafe if not done carefully and gradually – call the emergency services (113) for guidance instead.

Hyponatremia can be prevented by ingesting some salt with your fluids, or by mixing it in them, since eating while on uppers can be difficult. Due to uppers' antidiuretic effects, regular sports drinks might not suffice if you are very physically active and sweating profusely. You might therefore want to add a little salt to them, or buy a stronger product like Resorb, which is available in Norwegian pharmacies prescription-free. Also, try not to drink just to cool down, as this can lead to excessive fluid intake. Cooling down should primarily be done by other means than drinking, but it's a good idea to keep the drinks cool.

Note that some drugs, like cannabis, seem to counteract the hyperthermic effects (heightened body temperature) of uppers and may even protect the brain from oxidative stress.

However, cannabis should never be given to someone who has taken too much of an upper, since this may cause confusion, paranoia or even psychosis. Emergency room doctors will usually give a fast-acting benzodiazepine in such cases, but bear in mind that benzos are downers that can have dangerous interactions with other downers, such as GHB/GBL, alcohol or opioids.

It should be noted that MDMA (the active drug in ecstasy and molly) has sexual effects that are different from those of typical uppers. While many think MDMA makes people horny, this is often not the case; instead, it tends to make people seek intimacy, both physically and emotionally, and some find that they may develop romantic feelings for a partner on MDMA.

MDMA will often have a non-sexual quality to it, as it can reduce genital sensitivity even though other areas of the body are sensitized. It also mimics the "postorgasmic" state by triggering the release of the hormone prolactin, which can make it difficult to achieve orgasm and may facilitate "cuddling" rather than sex.

However, when MDMA is combined with other drugs, like GHB/GBL or psychedelics, the desire for sex may increase significantly.

MDMA can make people very trusting and suggestible, more so than other uppers. This effect is something to bear in mind when having sex with someone you don't know well, as it can make you more susceptible to being taken advantage of, or talked into performing acts you normally wouldn't perform, or sharing sensitive information you normally wouldn't share. It can therefore be wise to use MDMA only with people whom you really know and trust.