I bought mine from the UK, shipped to me in the U.S. I take 300mg, twice a day. I was prescribed for 400mg a day, but I choose to take 600mg because I haven't experienced anything such as anxiety. I would be fine at a total of 400mg once a day. I don't take mod consistently, when Im off of work and feel like I had a good nights rest, I will take 100mg in the morning and possible not take it at all the next day. Sometimes I simply forget to take it because it isn't addictive other than maybe the addiction to noticing that you are much more alert.
"How were you prescribed?"
I work 12-16 hours a day, 2 days on, 2 days off, 3 days on, 2 days off, 2 days on, 2 days off. When that cycle is complete, I switch from working "Days" which is 6:30 A.M. - 7:30 P.M. - and then to Nights, which is 6:30 PM until 7:30 A.M. - Often I end up working a couple extra hours per shift. This is called "Southern Swing" and what most U.S. manufacturing will eventually lead up to. After 2 years, most people that work this schedule experience lethargy during their days off which essentially reduces the quality of life and poor sleep when sleep is needed. For some people, this leads to narcolepsy, not being able to stay alert, etc. I work with highly hazardous chemicals such as Ethylene Oxide and improper use could blow up half of my town.
My insurance covers it, but constantly fight me on it and often request I take another sleep study or "do this or that" which is just a barrier that they are presenting to me to prevent covering it because Mod is expensive for them and don't feel it would be as bad to restrict purchasing this instead of something like heart medicine and things like diabetes medicine that other people actually "need." This is why I often buy it from a company in the U.K.
If there are negative side effects, I haven't experienced any yet. I am a borderline advocate for it because people today work so much more than people in the past did.
I dislike when people compare Mod to NZT in the film "Limitless" lol, but I hate to say that there are similarities.
After 2 years of usage I have:
Learned the German language and can read books in German and have a conversation in German. I have no prior experience with the language.
Greatly improved my study in Chinese (Mandarin) - I probably pressed maybe 4 years of non-immersive study into 6 months. Upon immersion, I feel nearly fluent.
I learned Python after being a non-programmer and built a database that helps me with arbitrage between eBay and Amazon.
I am in the process of learning JavaScript and feel comfortable enough with it that I could probably get a job as a developer.
Greatly improved process functions at work, and currently assisting in switching our drying process (of modified corn starch) from steam to natural gas.
Implemented a performance and tracking system of how well 24 employees were doing in comparison to each other and meeting goals.
If I experience bouts of hyper-focus, aside from writing long posts such as this one, I browse Quora for literally hours. From Quora, I read wikipedia for further insight. From Wikipedia, I order books for further information. This is what lead me to learn Python and Javascript.
If you are new to Mod, I suggest taking 50mg (which will likely be a partial pill) and a cup of coffee and seeing how your body reacts. If you feel anxious, this will eventually reside as the caffeine from the coffee will have a short term effect. If you feel fine and simply more alert, ditch the coffee and up your dosage until you feel more comfortable.