As 2many says, there is no precise number of pills. The strength varies from one to the other, as does what is actually in them. There are a number of drugs that can be pressed into pills to mimic the effects of MDMA, with very different levels of toxicity.
I've had some pills and crystals where 5 big damp things will barely do anything. Other times, I've had 2 homoeopathic sized ones and been having to put effort into holding things together as they start.
Like your friend, I have also gone through periods of eating far too many drugs. I'd be chain rolling through ounces of weed (literally rolling another before finishing the one I had, all day everyday), eating 5-9 pills a go, half an ounce of mushrooms, bags of speed that last other people a month and so on.
All I can say is, it's not necessarily going to turn you into a gibbering wreck or kill you, but the chances are getting higher and higher. If it hasn't happened already, she may find herself at some point feeling quite odd emotionally; particularly with amphetamine based drugs. Where you no longer feel simply free and open, but begin to interpret what people are saying differently. This is most obvious in meth users, when they start 'tweaking out' after days of being awake. But all amphetamines will do it to some extent.
I have tripped quite a lot of times, and on some pretty darn big amounts. However, I usually find it easy to separate what I see, think and feel during that time for normal life, as it is so immediate and so graphic it's easy (for me) to spot the difference. With amphetamine based drugs, the distortions are sneakier. They are not immediately apparent, they build up over repeated, heavy dose use.
What it sounds like your friend is doing, which is what I was doing, is switching from using them to abusing them; based on the frequency of use and duration. That every weekend needs drugs involved to be worth it. THAT is the downward spiral people talk about. Because pills will eventually loose their novelty as well, and then people will go looking for something harder, and harder again. As Panic in Paradise says, the more of it you eat and the more frequently you do it, the less interesting and special it becomes, and the more it is simply a way to 'mong out'. And 'monging out' is what meth and heroin addicts use drugs for. She needs to recognise that. Ask herself, why don't other people who do drugs do them every single weekend?
I could of coarse be entirely wrong about her, having never met her, but I would suggest, there is likely something upsetting her if she is doing them so frequently; which drugs won't fix. Heavy drug use is usually used as a means to cover up something else in my experience.
Even if the drugs don't turn you into a mess, which depends largely on your mindset, they are a sign that you are distancing yourself from the rest of society. A lot when you're using them that frequently. Which is ironic given how drugs like MDMA make people feel. Even around other people who like MDMA, she will become known as 'the addict' to avoid. The damage that does is nothing physical, but it can leave her standing on her own in the future. My friends in my teens used to get drunk and smoke weed. I didn't. When I first told them I was tripping in front of them, I could feel the tension and them not wanting to be around me so much. Years later, I would spend most of my days on my own and not speak to anyone else, because no one wants to know routine, heavy drug users. I've had seemingly endless, countless days where I haven't actually opened my mouth or seen anyone else. That is the real comedown. Years of silence.
It may be most effective if you show her the replies you get to this thread.
look for multiple, multi-continental, clinical abstracts - summed up in laymen terms if needed or possible.
