There is no 'safe' use of d-methamphetamine, it lends itself to abuse - for how many months will you be taking 15-30 mg? I can say with some confidence that after a few months of that dosage regimen, tolerance will occur and you will feel the need to increase your dose to achieve the same subjective stimulating/euphoric effects.
I've been using it for about 6 months now at this point with no increase in usage levels or dosage. Usage is very sporadic. Haven't even used more than a gram so far. Only taken ~25mg once in the past 2 weeks.
I don't even have to feel it for it to work. It seems almost subconscious. I can tell it's working due to changes in thought patterns, but there is no noticeable stimulant or euphoric feeling unless I've gone 2 or 3 weeks without taking a dose.
Usually my usage tends to stick to depression phase of bipolar when I can't just wait it out due to work deadlines or when 80/90 hour work weeks hit since I can't use caffeine.
The math works out at my dose level that it's much cheaper than adderall at the levels I use it, the noticeable side effects are negligible or non-existent, and it doesn't kick me into mania like caffeine does which is very harmful to me due to anger issues when I hit hypermanic.
So I'm still risking neurotoxicity no matter how little or sporadic my usage is, but the question is whether or not it'd ever reach noticeable or non-trivial amounts. Compared to the cost/side effects of adderall, the cardiotoxicity of cocaine, and the socio-toxicity (yeah I made that up) of caffeine... I guess it's still my best option. And all of those are preferable to me than the side effects of prescribed medication I quit taking 6 years ago, which include massive weight gain, emotional numbness, and loss of mental productivity.
I'd estimate I'm going to have heart/lung issues from smoking cigarettes long before I have neurotoxicity issues from the usage of this.
If y'all have any recommendations, suggestions or advice for harm reduction with my experience/current choice please let me know. Thanks!