I recently watched a documentary on the use of amphetamines during World War II. Germans were not alone in their use of performance-enhancing drugs during World War II. Allied soldiers were known to use amphetamines (speed) in the form of Benzedrine in order to battle combat fatigue. I had no idea amphetamines were also issued in Vietnam. I served with a short-range recon unit (Charlie Troop 1/9th Blues) so we didn’t need them.
During the Vietnam War, the U.S. military plied its servicemen with speed, steroids, and painkillers to help them handle extended combat.
Since World War II, little research had determined whether amphetamine had a positive impact on soldiers’ performance, yet the American military readily supplied its troops in Vietnam with speed. “Pep pills” were usually distributed to men leaving for long-range reconnaissance missions and ambushes. The standard army instruction (20 milligrams of dextroamphetamine for 48 hours of combat readiness) was rarely followed; doses of amphetamine were issued, as one veteran put it, “like candies,” with no attention given to recommended dose or frequency of administration. In 1971, a report by the House Select Committee on Crime revealed that from 1966 to 1969, the armed forces had used 225 million tablets of stimulants, mostly Dexedrine (dextroamphetamine), an amphetamine derivative that is nearly twice as strong as the Benzedrine used in the Second World War. The annual consumption of Dexedrine per person was 21.1 pills in the navy, 17.5 in the air force, and 13.8 in the army.
My Vietnam Experience 
I was at the 90th, CIF, in Long Bien, in early months of, through the end on 1970. Were there Drugs ? Yes. Marijuana, Heroin, Opium, and Meth. With the Exception of the Meth, I never saw anyone going “overboard”, heroin & opium Were , recreational, and not usually abused. We did have a young Sargent that really got hooked on meth, and he went nuts…There were deaths at the 90th due to Drugs, usually FNG’s just coming for the States with a habit and not realising how pure the stuff in Nam was, they were usually found with the works, still in their arms….
I was with the Air Force 823 Combat Civil Engineers Squadron (Red Horse) at Bien Hoa Air Base 1968-69 and we got hit often with 122dB directed at aircraft (mostly F4 Phantom). Quite a few were directed at our barracks at well which wasn’t that far from the aircraft. While on guard duty overnight at one of our construction sites, my two way radio screamed “Hit The Bunker” over & over. The base alarm screamed from overhead on a light pole and I scared shitless! The only thing that saved my life was a 7 foot high stack of ply boards (used for walls) of which I used as my perch and luckily I was on the opposite side from where the rocket exploded. Everyone knew the direction of where all the rockets came, Northeastward. It was about 2am & first there was a Hugh flash of light… like it was noon time… and then this explosion that rocked me to the core. The last words I remember saying was “It’s too damn loud”! The next thing I knew it was daybreak an airman from armory was shaking the crap out of me to wake me up. Problem was, I wasn’t sleeping… I was knocked out cold. A 2nd airman shouted, “ Does your radio work… we’ve been calling you for hours! For hours! They left me out there when they couldn’t contact me for Hours. Also a problem, I didn’t report anything! By the way, the ply boards were unusable because the shrapnel destroyed them on the other side, as i saw later. Life saved, but I was definitely scarred for most of my life. I should’ve had medical attention and maybe a Purple Heart. Absolutely nothing was reported. After that experience within days I had 2 fistfights, didn’t show up for duty in the armory, caught off limits with reefer joints. I received 2 article 15’s, lost 2 strips and heavily fined. For the next 6 months, my duty was limited to guard duty with blanks as my weapon. But I left Vietnam with over $10,000 as my guard duty overnight was in our construction yard with millions of dollars of supplies and equipment. My customer… was the South Vietnam Army who visited me every night I had duty. I also left Vietnam with 6 cartons of Kool cigarettes with every cigarette filled with reefer! I got a General Discharge, a 3912 with full benefits like medical and GI Bill!