I've had 3f from 3 different sources (bargain hunter) and I haven't noticed any real variation. I did notice different effects from the same bag though, I really think the effects you're talking about are down to you
Taken a bit less the last couple of days, tomorrow I really have to do none. Girlfriend is suspicious. My tolerance has made it easier to eat and sleep on but also reduced the positive effects, I've only really done a normal amount of housework etc the last few days. It's not even hard to quit, I mean I get pretty much no withdrawal, I just have to stop being a bitch
What ROA do you use? I only really have experience with vaping, which could possibly make any perceived differences more noticeable. I've used 6 vendors over the past year, ordering a minimum of 3 times consecutively from each and have noticed a huge variation in appearance, taste, effects profile and side effects - not just between vendors, but also from order to order.
However, I do believe the experience is also partly determined by one's individual body chemistry and metabolism as me and the Mrs very rarely experience the same effects simultaneously.
Throw in the fact that 3fpm also has four isomers with varying degrees of activity, adulteration with other substances, lack of quality control, different manufacturers, etc. then there are a significant number of variables involved.
After much experimentation and speculation, I believe there are 3 basic types of 3fpm 'powder' available at any one time (the crystal and glass varieties have not been properly researched in my lab so are not included here):
1. 'The Rusher':
Fluffy white powder, can be clumpy if damp. The vapour has a taste of plastic, but also 'earthy' in a spunky type of way. Melts to a clear beetle and leaves no trace on the foil - often hard to locate beetle when fucked. Typical effects consist of a crack-like rush upon exhaling which can sometimes be quite overwhelming and can cause slight nausea. This is soon followed by a calm euphoria often accompanied by a marked increase in libido - to the extent that it's 'Zip, lob' soon after lift off. With redosing, MDMA-esque qualities become apparent, e.g. empathy, openness, change of colour perception, visual effects and the sense of being enclosed in a timeless bubble. These effects are so pleasant that compulsive redosing is often unavoidable and days can be lost to vaping, sexual activity and staring at the wall watching imaginary pictures. After 12 - 16 hours or so, the 'doldrums' are reached, where redosing seems to be having no further effect. However, with perseverance, the next level can be attained when the active metabolites kick in, which gives the experience a more amphetamine type feel. From now on, the immediate vaped effects occur concurrently with the metabolic effects leading to a steadily increasing euphoria which gives the illusion of being infinitely sustainable, but sadly isn't. I find the law of diminishing returns is invoked between 3-5 days
Unfortunately, this type is the most caustic and also produces the worst physical side effects - vasoconstriction, tachycardia, headaches, bruxism, cramp, general aches and pains, foul body odour, blurred vision etc. - but the recreational effects make it apparently worthwhile.
2. 'The Creeper':
A dry granular powder sparkly in appearance. More of a chemical taste when vapourised. Beetle initially runs clear but turns yellow or amber after a few reheats. Can leave a light trace on the foil. Initial effects take higher doses to achieve and feel more like a conventional stimulant rush than crack rush. No empathy, minimal increase in libido and no after-rush tranquility. This type seems disappointing at first, but when the metabolites kick in, a similar level of euphoria and stimulation can be achieved to that of 'The Rusher'. The effects creep up slowly, hence the name. Side effects are also usually less severe and though the desired effects are less pronounced, it also has a less toxic feeling to it.
3. 'The Other':
This type appears to be a mixture of the previous two types in varying proportions.
Needless to say, my favourite is 'The Rusher'. It's a hard hitting filthy dirty slut of a drug, is recreational rather than functional, has kept me off opiates and has totally transformed our love life. However, the other types have their merits also, but I can't help feeling cheated if I don't receive 'The Rusher' in my order.
TL.DR I'm off me tits again, just ignore me...