Hi, years ago I was on Ritalin, and don't remember much about it except it seemed to be effective for a long time. Then I got switched to Adderall IR. I was on that a long time. Now I've recently gone back to Ritalin since the Adderall seemed to not work as well anymore.

From my research, I've found that Ritalin has a half-life of only 2-4 hours, with oral bioavailability of only 11-52%! And d-amphetamine (Dexedrine and biggest ingredient in Adderall) has a half-life of 10-28 hours with oral bioavailability of 75%!

That is a huge difference! It seems obvious to me that something with only a 2-4 hour half-life and such low biovailability is going to be way weaker than Adderall.

With my Ritalin dose being almost the same as my Adderall dose, it's like getting my medication cut at least in half, if not more so.

I am going to try to get switched back ASAP.

In the meantime, does anyone else have a problem with Ritalin's short half- life and low bioavailability? The 11% figure particular has me concerned. If true, only 11% of the dose is actually getting used by the body?

And with a 2-4 half-life, and being a fast oxidizer as I am, I would have to continually dose every 2 hours at the latest to avoid a crash. Probably sooner since if the half-life is indeed only 2 hours, the dose would peak at around 1 hour after taking it, right? And it takes about 30 minutes for the onset.

So I view Ritalin as like a flight from Chicago to Minneapolis- about 50 minutes total, with almost all of it being the takeoff and ascent, and then descent and landing. The actually steady flying time at the cruising altitude is so minimal you barely notice it.

What I can't understand is how anyone could benefit off of this. The only way I could see it is if you have, say, a 2 hour conference that you need to be on top of your game for. So you pop a Ritalin right beforehand.

But in that case it seems like Ritalin is only good as a short-term performance pick me up. Hardly to treat ADD or ADHD which lasts all day, every day.

Any thoughts?

Taking Ritalin every 2hrs is not unusual. And also, you cannot compare dosages between different medications. 50mg of Adderall is not equivalent to 50mg of Ritalin. Rules of thumbs abound for deriving equivalent dosages, but they're just that, rules of thumbs, they're not formulas.

Also, as a woman approaching 40, your biological chemistry is changing. You would be a different person to the person you were years ago. So just because you were on a specific dosage of Ritalin before, doesn't mean it's the dosage you need now. Had you stayed on Ritalin, you might find your dosage now would be different to your dosage before.

For some people, they prefer the short acting instant-release stimulant medication. They like the flexibility it provides. Some people treat their medication like reading glasses: you only use them when you need them.

You're right- different medications, different people. I think it's just that when I started I was a "virgin" on these meds, so the relative weakness of Ritalin wasn't an issue. But now going back to Ritalin after Adderall, it's like going back to drinking wine coolers when you have a Jim Beam whiskey habit. It's just not gonna cut it!

And I suppose others really take it only as needed. But for me I need it to work all day if I'm going to get any work done or do anything that requires organization, motivation or focus. I can take a break from the meds if I'm just going to be lying on the beach all day or sleeping in bed all day or vegging in front of the TV all day. But since that rarely happens most of the time I need the meds to be working to provide extended daily coverage rather than having to redose every hour or so and time it just right as to not start crashing.

But different strokes for different folks!