Does anybody take 15 mg of XR (adderall of course)? I weigh about 140 lbs and was wondering if this dosage is effective all day for a person of a similar body weight. 20 mg seem too high for me, and it seems like 10 is only really effective for about 4 hours. I like adderall, because i think that 10 mg really gives me a balanced level of focus and .... um social confidence? But again it only lasts four hours or so. Whereas the 20 mg seems to make me shut down (become irritable etc.) Also, would taking 20 mg on a full or empty stomach make a significant difference?

would taking 20 mg on a full or empty stomach make a significant difference?Hi Biohazard, and welcome to the forums.

Significant difference? From my experience yes.

Let's say you're filling your stomach with foods or drinks that are acidic (low pH) like, citrus fruits & juices, tomatoes or tomato sauces or tomato juice, sodas, etc. Foods and drinks that contain acids can & often do lower the absorption of amphetamine.

On the flip side of the coin, things you put into your stomach that have an alkalizing (high pH) effect like, Tums/Rolaids (calcium carbonate), soda crackers, baking soda, etc. These things can & often do actually potentiate and increase the absorption of amphetamine.

As far as how significant the difference is between a full or empty stomach, well it can often depend on the person, or the pH of what was eaten. We each can and do respong to these drugs in our own unique ways more often than not.

There is also some evidence that shows that a high fat diet can also have an effect on the absorption of Adderall XR.

Below is a quote, and a link which touches on the issue of whether of not there is a difference in effect between a full stomach or an empty stomach:

"individuals in the study who took Adderall XR,<SUP> </SUP>an extended-release formulation of mixed amphetamine salts,<SUP> </SUP>displayed drastically lower early blood levels when taking the<SUP> </SUP>medication with food compared with taking it on an empty stomach."<SUP> </SUP>

http://pn.psychiatryonline.org/cgi/content/full/37/15/19-a

Depending on how long your days are you may consider taking the 10mg 2x a day, one as soon as you wake up, and say one 6 hours later.. this seems like it would work with minimal effects on your sleeping.. unless you sleep more then 8-9 hours a day.

I'm 190 lbs, I started on Adderall XR10 a year ago, after a few months went up to XR20, which was too much, I was talking too fast. XR15 is working well for me.