From the depths of my ass I bring you: 0.25-0.5mg/kg or 35mg for a 150ish pound individual. Seems like the area where things start being flagged for potential neurotoxicity in some studies I've read. However, this is by no means definitive.
I know you meant pharma amps but ill add my street amp data and experience in terms of dosing since it might help other readers and honestly its a topic that needs some attention due the issues and risks with ensuring accuracy and safety. I tried to be detailed to ensure no accidental misuse of the methods
Its hard to say really with street meth since its almost impossible to manage this to absolute certainty or perfection in terms of measuring doses. There are a number of problems with ensuring accuracy. There is no easy way to measure this effectively, in my experience, and i dont have a scale or anything like that as im sure many meth users do not either since apparently buying more meth instead of a scale makes more logical sense. Who am i to argue. Also i dont trust the accuracy of some of the eyeballing methods. So this is what i do instead based on leanings from other experienced users.
With all that said, safe dosage for street meth in crystal form specifically is usually reasonably sized or what is often called medium or average lines as per the line measurement standards that I learned with previous coke usage (as determined and prob equal in my case mostly to the width of a credit card, but a bit skinner then a line of coke usually would be as per normal.
Any amp user will know what i mean and in terms indicating size by match length or other inaccurate means leaves to much room for error in my opinion and therefore risky. Whos to say matches are the same size here then they are elsewhere for example?
Then secondly the dose is also largely influenced by how many shards fall out of the bag for that particular dosing session, and this can differ to a significant degree and impact accuracy, more then some might think, so it does cause additional issues with accuracy and my investigations have shown this is mostly caused by the shard consistency/size, which differs significantly even within one order or gram, and then weight as part of this factor.
This issue unfortunately influences the potential "fall rate" consistency effecting the volume reliability you might get each time you attempt to shake a specific quantity out of the bag (usually little ziplock one i my case which has the added issue of the substance getting caught or delayed on the "zip/close lines or groves on the bag" and therefore further impacting the end result quantity and overall accuracy. Hopefully others have superior packaging and dont have this added nightmare to deal with.
I have asked my guy to please ensure more consistency in the shard format he provides and use different bags that improve the flow or fall rate to a more consistent level that can be relied upon at least to a small degree. I did say this would help users more tightly control dosages but I have not noticed any change in deliveries and im sure these guys don't frankly care how safely we dose, once they make the sale, its not their concern. Pfft.
I could crush it all up to help things but then the product would be out of the bag and again we have the issue of inaccurate dosage. Cant do the whole bag obviously, crushed or not, it would still be to much either way. And crushing it in the bag can damage the bag and spill product, a nightmare for those with carpets causing issues with product retrieval later one as well. Or at least it does sometimes tear with my low quality zip crap baggies.
It was a silly choice honestly but I do prefer it to stupid wrapped up bits of plastic like with coke since once again the suppliers dont consider that users might not be plastic knot tying geniuses like they are and an opened piece of plastic that cant be tied up again, especially not by a jittery coke head is just stupid and leads to spillage of product often then not onto some germ ridden surface like a public toilet seat. Perhaps i dont give them enough credit and spillage is the goal leading to faster reordering. Damn Scum.
Back on point, I dont see why i should have to deal with formatting the product when its the suppliers job to provide the format requested, its a matter of principle really so i refuse to do this myself, though i admit its good to see shards in your purchase as a way to ensure quality to some degree. Seeing powder might concern me over getting shitty cut amps or that vile amp sulphate they try to pass off as real amps sometimes. Its not ideal overall but i dont see any other way to improve this situation as long as the suppliers are not willing to see reason.
Also orally, my other and only ROA, the dosage is greater usually in the beginning for new users since the shards that fall out are still intact and it seems to the discerning eye as if the dose is smaller then it really is compared to crushed version used for nasal (crystals are compacted see), so usually oral is a greater dose then nasal, but not sure to what degree exactly, however it was certinally felt as a stronger dose.
Experienced users will have taken note of this and modified oral volume to take this into account, but beginners should be careful of this risk. Oral is still very efficient and problems with increased dosage can be felt strongly in this regard, though usually only as more fun and good times, but still.
I have factored this issue in myself as well and try to reduce the oral dose appropriately, but in this case its still somewhat inaccurate and its not always possible to ensure a max amount, and not a crumb more so to speak, since when the shards fall out the bag sometimes a few sneak past, it cant be helped, this again as mentioned is due to the consistency issue with different sized crystals and this still often skews my attempt at controlled dosage. It gets better with practice however but it will never be perfect.
I understand however that the few that make it past is not a cause for concern or anything and will not be enough to cause any sort of issue, beyond slightly increased effects and therefore all things considered it is still an acceptable risk. It still bothers me though since im anal about these things and I would prefer to be able to ensure fully accurate dosing. Any ideas on this beyond finding a new guy who is willing to listen to customer feedback?
Now in terms of the health issues as queried, for those exact doses and for me personally, as we all differ, I have not noticed or felt any neurotoxicity or issues in this regard. I do however ensure proper health habits, supplementation, good old ch mag, i love thee and even go as far as proper glutathione supplements for some extra powerful anti oxidant love just to be safe (which i believe is somewhat related to neurotoxicity?).
I will say that so far compared to MDMA, which destroyed my brain in less time then meth has been used, with zero bad effects in comparison, it is seemingly harmless, though im sure thats not quite true, but at least in my experiences and at my very specific doses it seems ok. I believe dopamine is more forgiving then Serotonin in this regard, which is a shame since this just seems like an unnecessary and cruel joke on the MDMA users to be honest with many like myself having to learn this the hard way.
Anyways, others may differ obviously and my specific doses might not be right for everybody. Any improvements or suggestions on my method would be appreciated.