This statement makes little to no sense by itself.

Take as much aspirin as a psychoactive dose of LSD (say 100µg) and there will be no toxic effect from aspirin, but take as much LSD as an active dose of aspirin (400mg every 4 hours for an adult to to treat fever/pain) and you have a dose of 33 times the LD50 of LSD which is quite toxic imo.

What's important is the average active dose as a fraction of the toxic dose. For asprin (400mg dose, 70kg body weight), that's about 1.9%. For LSD (100µg, 70kg), that's about 0.7% (numbers gathered from wikipedia).

Because of its minute dose, LSD has the problem that it's hard to know how big the dose you're taking is, since most people don't have analytic balances in their kitchens. Even still, most people are going to need to take at least 10mg of LSD to overdose, even with the highest toxicity results published, which is pretty easy to distinguish from a high recreational dose of 200µg.