She Chewed on Cocaine Gum with Churchill
If you are familiar with Victorian medicine, you are aware that there was no distinction between what we now refer to as medicine and opioids. As painkillers, heroin and cocaine were frequently used, and cocaine in particular was found in everything from chewing gum to wine.
Before Coca-Cola became popular, you could purchase Coca-Bola, a chewing gum that contained up to 10 lines of cocaine in each piece. Who's going around downing 10 lines of blow on a regular basis? Victoria was rumored to have chewed something similar, with a young Winston Churchill no less, which must have had her tripping the light fantastic.
The gum's advertisements say that it relieves exhaustion and gives the user extra energy for work. You might be able to quit smoking with its assistance. There is no information on how long the Queen used it, but it must have given her a little boost.