The above points about “doping” with steroids apply here. Use of stimulants is hazardous, especially in critical situations requiring good judgment. Studies at low altitudes demonstrate users having poor judgment and being more likely to have a serious automobile accident. Amphetamines have caused death through a variety of mechanisms and produce tunnel vision, which can be hazardous in mountain environment. Modafinil, which has been touted as a modern drug to ward off sleepiness, appears to be difficult to self-monitor (how well you perform) after sleep deprivation. These agents might increase pulmonary artery pressure and lead to HAPE, but there are no studies of any such agents at altitude. The so-called Triple D (dexamethasone, dextroamphetamine, and Daimox) is used by some climbers, just as heroin used to be taken by famous surgeons. I used to carry dextroamphetamine in my medical kit years ago and never used it. Now I don’t carry it at all. Use of such agents has been presumed to be the cause of death in some climbers when it affected their judgment, causing them to do something stupid. One climber described having to consciously prevent himself from flying off the mountain while on amphetamines. My sense is that there is considerable use of these agents and likely considerable harm, including death as a result. I speculate that if climbing at altitude was safe, there would be a different population who did the activity. Adding other potential risks may not matter that much for some.