This article is part of "Safe Sesh", a VICE harm reduction campaign produced in collaboration with The Loop and the Royal Society for Public Health. Read more from the editorial series here.

You may think MDMA is just a chemical that makes listening to tech-house seem like the most important thing in the world, and in many ways you're right. But there is more to it than that: while still relatively low compared to the harm caused by alcohol or tobacco, deaths and hospitalisations due to MDMA and ecstasy are on the rise globally, thanks to producers making stronger drugs than ever before.

In 2015, the purity of MDMA in the UK was recorded as being as high as 83 percent. The same year, the average ecstasy pill contained 100mg of MDMA – far more than the 20 to 30mg seen in 2009, or the 50 to 80mg common in the early rave days. Now, drug testing organisations regularly find pills containing over 150mg of MDMA, and sometimes up to 300mg, i.e. enough to make you seriously ill, or – if you take the right precautions – make you rush, gag a bit, have a lovely time and then an incredibly sad time for the following week.

With other drugs, such as cocaine, you're fairly unlikely to come across super strength batches unless you're a professional drug importer or can be bothered to work out how to use Bitcoin. With pills, it's the new normal. To find out about the risks associated with super strength pills and MDMA, and how they will affect you over the course of a night, I got in touch with Oli Stevens, a drug scientist, writer and researcher for DrugScience.

THE FIRST HALF A PILL / BOMB OF MDMA

First off, if you're going to use ecstasy or MDMA, you should know how to use it safely. When it comes to tablets, experts advise that you should always take a half – or, better yet, a quarter – and wait to see how you feel before taking the whole pill. For MDMA, follow drug welfare organisation The Loop's advice to crush it, dab a bit of it and wait for its effects to kick in.

As for those effects:

"MDMA is a stimulant that can give feelings of exhilaration," says Oli. "Unlike typical stimulants, though, it also produces distinct social and emotional effects, and alters perception." He adds that "MDMA also has the effect of increasing levels of the hormones oxytocin and vasopressin, which may be involved in making users feel emotionally connected."

So in about 20 minutes to an hour, when the chemical has had time to do a little shuffle around in your bloodstream, you'll start to feel that weird, semi-pleasant lurch in your stomach, and get bang into chewing your own tongue.

THE NEXT HALF A PILL / BOMB OF MDMA

Experts advise leaving two-hour intervals between doses, and with super strength pills and MDMA it's important advice to follow. Because many people expect their MDMA to work right away – perhaps due to the popularity of more immediately noticeable drugs, like coke and ket – they take more before the true effects have come on. Don't do that. It is an objectively bad idea.

"People often conflate the ideas of purity and dose," Oli explains. "With 'weak' MDMA, i.e. high purity, low dose, it will simply bring about lesser effects. With 'strong' MDMA, i.e. high purity, high dose – which is what we are facing with ecstasy pills at the moment, where pills of 200mg-plus are seen – users will experience more potent positive effects [if they properly manage how they take it]."

If you've been patient and not spanked your whole gram in one go, you'll be two hours in, euphoric as your dad was the day you left home, handing your number to the bouncer in the genuine belief he's going to teach you Muay Thai the following day. If you've been too eager, it can lead to problems.

"High doses are a serious issue if users are still downing two at the start of the night, treating them like 100mg pills," says Oli. "It brings an elevated risk of the main causes of death from MDMA, which – although not widely known – is very rarely an actual overdose, but heatstroke, or sometimes severe dehydration."

An FCB pill

THE REST OF THE NIGHT

Again, with higher purity MDMA and ecstasy, taking more and more throughout the night only ramps up the danger, while that initial euphoric period you're chasing won't ever be reached again, as that has a lot to do with the stuff going on in your brain during the initial shift from sober to spangled.

Sreally, you might actually be making your own night actively worse, which is a profoundly stupid thing to do to yourself.

"Anecdotally, it seems that taking very high doses of MDMA may only increase the energising speed-like effects of MDMA, not the euphoric or emotional effects," says Oli. "Unpleasant effects – like anxiety, feeling unbearably hot, over-stimulated, confused or anxious – are more likely the more you take."

You know what it's like: your legs are getting heavy, you're beginning to realise that, actually, this 45-minute chat you've been having about house plants is just not at all fun, and you figure the only thing that will glide you back to that blissful flickery-eye stage is another half. But it won't, because serotonin doesn't work like that.

WATCH: High Society – The Truth About Ecstasy

THE COMEDOWN

This is where basically all MDMA and ecstasy of any real strength is going to make you feel all weepy and just astonishingly shit for an unspecified amount of time. "There can be a comedown period which may last several days," says Oli. "In this period, users may experience depression, fatigue, anxiety, impaired concentration and insomnia."

Whether your pills contain 50 or 150mg of MDMA, 36 hours after you began, you're still going to be ordering a Meat Feast and welling up at Grand Designs, contemplating how late you can set your Monday alarm without making you too late for a day in which you're going to get absolutely nothing done.