- Oxygen in liquid form.
- A solution of hydrogen peroxide and other compounds that is reputed to have health benefits.
- 1880, St. Louis Courier of Medicine and Collateral Sciences:
- Under the name of " compound oxygen " or " liquid oxygen," it has been used in its liquid form by quacks, and has been sold as a patent medicine ; and has cured some who had experienced no relief from treatment ordinarily adopted for such cases.
- 1999, Penelope Oaks Colville, The Multiversa Strategy, →ISBN, page 220:
- To boost oxygen supply for health recovery or immune system support at the onset of illness, try daily use of liquid oxygen. For use internally, the ratios given below (for hydrogen peroxide, originally) are conservative.
- 2008, New Scientist and Science Journal - Volume 199, Issues 2663-2670:
- This was not just another quack cure. This was on sale exclusively from the duty-free trolley on Continental Airlines. What was it? Liquid oxygen, that's what.
- 2014, Joe Schwarcz, Is That a Fact?: Frauds, Quacks, and the Real Science of Everyday Life, →ISBN:
- For more mind-numbing claptrap, how about “all-natural liquid oxygen” drops under the tongue to fight jet lag, fatigue, hangover, and aging skin?