Ephedrine -- Staying in the blood stream

I posted this in the general Nutrition forum, but then when I saw the other threads in there (e.g. "I just ate 1/2 a gallon of ice cream", "Can I supplement my carb intake with beer"), I thought I might get a more helpful response here.

I am not a certified nutritionist, just an interested amateur :).

Someone asked a question about how long ephedrine will stay in your blood stream. While I have seen everywhere from 2-7 days after continuous use, I thought I would do a quick check to see how long it actually stays. This is in no way conclusive, but these are the facts I could dig up with a quick search. Please comment.

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From a scientific perspective, the half-life of ephedrine is not entirely certain in the human body, but the half-life of ephedrine taken as part of a normal EC stack (Bronkaid and caffine) is almost completely uncertain -- the only thing they really know is that it is prolonged.

For instance, here's a Merck study where the demonstrated half-life varies between 2-21 hours based on urine acidity. [url]http://www.merckvetmanual.com/mvm/in.../bc/214007.htm[/url]

However, and this is the important part for our purposes, this study talks about the effects of ephedrine as infused with beta agonists: Choo J, Horan M, Litlle R, and Rothwell N. Anabolic effects of Clenbuterol on skeletal muscle are mediated by beta2-adrenoreceptor activation. Am J Physiol 1992; 263:E50-E56.

Basically, infusing ephedrine into a beta agonist greatly prolongs the half-life of ephedrine. There are obvious reasons why this would be a beneficial result for someone producing beta agonists. However, every clinical study I've ever seen on "E/C stacks" uses pure ephedrine and caffine.

If you've ever taken pure ephedrine and caffine (or talk to people who have), they will tell you that the results basically suck compared to a "normal" E/C stack of Bronkaid and caffine. This is because ephedrine absorbs rapidly into the blood stream, so you get a big rush, but then it leaves quickly as well -- you're left with this rollercoaster effect that is not very beneficial for your body.

Infusing it with a beta agonist allows long, slow reception and prolongs the half-life of ephedrine significantly. This has to do with ephedrine binding to beta receptors, yada yada, you see where I'm going. The study basically said that the half-life becomes indistinguishable from the half-life of the beta agonist.

So you are correct if you are talking about pure ephedrine and caffine -- it has a short half-life. That is, as far as I can tell, the main reason why people who buy pure ephedrine for E/C stacks have horrible results, while those who buy beta agonists (like Bronkaid) with ephedrine in it for E/C stacks have very good results.

However, there is another point that should be made. There are many studies that show the half-life of renally-excreted substances varies depending on the amount and duration of use. All these studies conclusively show is that the more you take, and the longer you take, a renally-excreted substance, the longer it ends up staying in your system.

Let's take a very easy example -- alcohol. Your body metabolizes alcohol at approximately one drink per hour. If you have one drink per hour, every hour, your body will continue to metabolize them (unless your liver or kidneys fail) normally, and if you test your blood at the end of every hour, you would have little to know trace of alcohol in your blood. Obviously this is an average, and is greatly effected by personal circumstances. But say you drink 3 drinks per hour for 2 hours. At the end of those two hours, your body can only metabolize 2 of those drinks, so you still have four left in your system. If you have 3 drinks per hour for 12 hours . . . well you see where I'm going.

Ephedrine is the same way. It is renally excreted, which means that it has to be processed through the kidneys and excreted in your urine. That is why, under the Merck study referenced above, the half-life of ephedrine (taken in 12mg doses) varies from 2-21 hours depending on urinary pH.

So if you have bad kidneys, or overload your kidneys, it will take much longer for your body to flush the ephedrine. Compound this with the effect of infusing ephedrine in beta agonists, and you have a situation where ephedrine could stay in your body for days beyond its chemical half-life.

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Cliffs:
-- Depends on your kidney function, can take anywhere from 2-21 hours to flush by itself
-- Longer if you take it as part of a beta agonist (e.g. Bronkaid)

I use pure ephedrine in EC stack since I've never seen bronkaid in Canada (and pure ephedrine is available freely), and have never had terrible results or a roller coaster ride. Just long smooth over-stimulation and hunger suppression.

Even with the fastest half-life you suggested of 2 hours, that still means the ephedrine will be having 25% of its initial effect after 4 hours. Hardly a sudden crash, combine that with the fact that EC stack is usually dosed 3 times a day approx 4 hours apart, and you can see it makes little difference what you use.

You also then have to consider sleep patterns. With most people, if they dose within 4-6 hours of bed time, they will have trouble sleeping. Extending the half-life of ephedrine even further would only exacerbate the potential sleeping problems associated with it's use. I think in this situation it doesn't particularly matter how fast it is metabolized, as long as the last dose is taken at the appropriate time.

Overall the point being, there is not necessarily any benefit to ephedrine being metabolized fast or slow. Slow might save you some money, and fast may give you some extra control. Either way any difference in half-life is likely moot if the proper dosing protocol is used.

For those purposes, you would be genearally correct. However, as that study (and a couple more I did not cite) mentions, the absorbtion speed is different from the half-life. The half-life is how long it takes your body to excrete half of the ephedrine. It actually fully absorbs in 30-60 minutes, and after the first hour there is a dramatic drop in its effectiveness. The study ended up recommending that you take half doses of ephedrine and caffine every 2 hours instead (if taking straight ephedrine) to regulate absorbtion. I would also point out that you have not taken Bronkaid, so you don't really know the difference between taking it versus taking straight ephedrine.

This question was raised in the following context though: Someone who had been taking an EC stack for 3 months wanted to stop taking it before going on vacation b/c they were planning on drinking heavily. Under those circumstances, they would have to allot enough time in between the quitting and the drinking to prevent risk of kidney damage.

Also, there is the context of drug testing. Ephedrine is banned by many major sanctioning bodies, as well as some jobs. If you are being drug tested, you would need to know how long it takes for ephedrine to leave your body.

I Imagine just based on chemistry the Ephedrine HCL will dissociate completely and be the equivalent as pure ephedrine. Self-Guinea pig evidence supports this theory. I feel a million times better on primatene then bronkaid. Although i'm probably full of sh*t.

Anyone else realize that ephedrine IS a beta agonist ? Caffeine is not. Caffeine blocks the adenosine receptor, the metaphorical equivalent of putting a brick underneath your brains "brakes". Inhibiting adenosine receptors does cause higher secretion of epinephrine and norepinephrine.

So how long can ephedrine still be detected in your system for sporting event drug tests for example?

wow good read!!

My local CVS has primatene, and I am super grateful. I've been taking it thusly:

1. 25 mg/100 mg/16 oz coffee (roughly 100mg caffeine)
2. 25 mg/200 mg
3. 12.5 mg/200 mg

On a day-to-day basis I feel like a million bucks. I've never compared to Bronkaid nor pure ephedrine HCl, but I can say that the primatene/caffeine combination has purely great side effects. Fat is flying off too.

[QUOTE=Transhumanist;812511311]So how long can ephedrine still be detected in your system for sporting event drug tests for example?[/QUOTE]

Likely a few days, depending on dosage and how sensitive the testing is. Extra vitamin C really increases clearance rate if you're interested in speeding that up...