As the Ars team convenes for two days of meetings in Chicago, we're reaching back into the past to bring you some of our favorite articles from years gone by.

Ah, sweet, sweet caffeine. Whether your chosen delivery device is a Triple Red Eye from Starbucks or a liter of Mountain Dew, nothing beats the gentle jolt into full wakefulness provided by the humble C 8 H 10 N 4 O 2 molecule. Oral delivery by means of caffeinated liquids has long been the preferred method of getting one's caffeine buzz on. In a cruel twist of fate, some people are unable to brew a pot of coffee, order a latte, or figure out how to open a can of Mountain Dew right after waking up, due to that very same lack of caffeine.

What's a caffeine-loving geek to do? Enter Shower Shock. In the search for ever-more-efficient ways to ingest caffeine, someone came up with the bright idea of adding caffeine to soap. That way, all you need to do is to stumble out of bed and into the shower, wash with a bar of caffeine-infused soap, and you're well on your way to full wakefulness.

I'm a long-time caffeine addict, or as we used to say in the 1980s, a Coffee Achiever. I've tried with varying degrees of success to kick the habit, and I am even married to someone who avoids the blessed molecule completely. I've managed to stay off of it for a couple of years on more than one occasion. But in the end, I always come stumbling back to the precious bean.

My current intake comes primarily in the form of coffee. On the weekends, that means approximately a quart of Starbucks Sumatran, French Roast, or Komodo Dragon coffee freshly ground and brewed using a paper cone filter. I can accomplish nothing meaningful on a Saturday or Sunday morning until I've sat down on the couch with the newspaper and made my way through at least half of the morning's brew. During the week, I generally hold off on the coffee until I get into the office. I either grab a large coffee at the cafeteria in my building on my way in, or brew some right after arriving. Either way, I'm here, but not here until I've got some coffee in my system.

After acknowledging the depths of my addiction and subsequently resigning myself to it, I was intrigued by Shower Shock's promise of a cup of coffee in every wash. Depending on a number of factors, a regular cup of coffee contains anywhere from 120 to 200mg of caffeine. Shower Shock says each bar delivers 12 washes of 200mg each. So if nothing else, I was hoping the soap would give me a nice little jump start on my daily fix. Oh, and I was hoping it would get me clean, too.

Hardware test bed

No Ars review is complete without a discussion of the test systems.

Test bed #1:

38-year-old male

Heavy caffeine user (about 5 cups daily)

Shares responsibility for monitoring two processor-intensive

child processes

child processes Average uptime per day: 17-18 hours

Spends too much time in front of a computer

Test bed #2:

Age not disclosed (I value my marital bliss, OK?)

Avoids caffeinated beverages entirely

Spawned two child processes, has primary responsibility for

monitoring

monitoring Average uptime per day: 16-17 hours

Thinks I spend too much time in front of a computer

Test environment

The shower. Where else?

After my Shower Shock arrived, I deviated from my usual Dove + Neutrogena facial bar combo. I use the Dove to keep my skin from drying out during the winter and the Neutrogena because my face thinks I'm stuck in adolescence. Instead, I jumped into the shower and lathered up with the Shower Shock. Now, in addition to containing roughly 2400mg of caffeine, each bar is also heavily loaded with peppermint oil. Not long after lathering up, I got the feeling that not only had I just gone for a brisk stroll in the peppermint rain through the peppermint forest of the children's board game "Candyland," but while walking through the forest I had tripped over a peppermint tree root, fell into a peppermint mud puddle, slid down the slopes of peppermint hill through the peppermint grass, and landed in the peppermint pond.

Wanting to give my skin the maximum possible exposure to the beneficial effects of the soap, I soaped myself up and let the lather sit for a few minutes on a few areas of my body, including my big, bald head. I performed the rest of my daily ablutions, dried off, got dressed, and prepared to leave for work. In addition to feeling the effects of the peppermint oil in the soap, I also fancied I felt a bit more alert. Upon arriving in the office at 8:30, I felt perky enough to avoid the coffee maker for about a half-hour, a notable change from my usual habit of making a beeline to the kitchen upon arrival. I still downed most of my usual ration of coffee, but it seemed to me the soap had made a difference, giving me a small—yet significant—start on my daily fix.

Curious as to whether I was really feeling the effects of the soap or the mere suggestion of an effect, I asked my wife to take one for the team and try the soap. She has been off caffeine since just after we started dating. My love for her was (and is) so strong that I was willing to weather the stormy seas of caffeine withdrawal early on in our relationship. She has been off the stuff for over a decade, and drinking a cup of regular joe will give her nausea, the shakes, and a jittery feeling that will last for several hours. The most recent occurrence was a couple of weeks ago when a barista at Starbucks failed to hear the "decaf" part of her latte order, which was evidenced by the usual symptoms along with her staying up until nearly 2am after drinking it at around noon.

So with much trepidation, she showered using the soap. The result? Not long after exiting the shower, the familiar and unwelcome symptoms of caffeine ingestion appeared. They lasted for a few hours. They weren't as severe those that follow a tall, accidentally-not-decaf latte, but she definitely felt... something.

But what was that something? We all know the power of persuasion and the reality of the placebo effect (the infamous "informed consent placebo risk"). Were our minds playing tricks on us? Were we confusing the tingling of the peppermint bomb in every wash with the bodily absorption of caffeine? In conversations with the crack Ars scientific staff, Dr. Gitlin and Dr. Timmer both expressed doubt as to how well caffeine could be absorbed through the skin. They informed me that while the molecule is very water-soluble, which allows it to be easily absorbed by the body when it is consumed, it would have a much more difficult time making it through the skin. In addition, the bond between caffeine and soap might be so strong that the caffeine molecules would follow the soap bubbles down the drain instead of being absorbed through the skin.

Was the tingling and alertness (or in the case of my wife, the shakiness and jitteriness) all in our mind? It could very well be. I've continued using the soap almost daily, and will do so until our three-bar supply is exhausted. (The manufacturer says each bar is good for 12 washes, but I'm approaching 10 uses and the bar is roughly half gone.) I'm still drinking about the same amount of coffee as before. Of course, the alert feeling could also be from the peppermint. Peppermint oils and soaps can be tingly by themselves, and we all know what happens when you bite into a York Peppermint Patty.

I will say that I feel more alert after showering with Shower Shock than if I stick with the Dove. I arrive in the office fairly alert every morning, as opposed my the usual mostly awake state. I suppose that someone, somewhere will do a clinically controlled, double-blind study on transdermal caffeine application. Until that time, I'll cautiously recommend caffeinated soap to caffeine addicts looking for that first hit of the day—provided they don't mind spending nearly $7.00 on a bar of soap.