In ancient Greek and Roman times, they discovered that silphium, a plant usually used for seasoning purposes, had a contraceptive effect. However, how useful it actually was for anti-pregnancy, we cannot know. It was harvested to extinction since it was worth more than its weight in silver. After the disappearance of silphium, one of its relatives called asafoetida was used as a replacement. However, overdosing could be lethal. These examples are not the only ancient methods of birth control. It is documented that in other ancient societies stones or garlic was used to block the vaginal passage. Others chose to apply plugs of grass, cloth or sea sponges.
A little later, in the fourth century BCE, the father of medicine, Hippocrates, however great his legacy is, suggested that women could drink copper salt water to prevent pregnancy. Even though he claimed it was effective for a year, it was still toxic. Just when you thought you have heard the craziest birth control methods by now, there is more. The Greek physician and gynecologist Soranus declared in the second century CE that women should hold their breath during sex and sneeze afterwards to expel the semen. Next to that, he advised women to jump backwards seven times. Unreliable tricks, for instance ejaculation interruption, had been widely used throughout the world as less harmful but also less reliable than other methods.
However, because of the harms, difficulties, and fallibility of these ancient methods, men and women continued trying to find better solutions.
(Source: Paul J. Carrick, Medical Ethics in Ancient World, 2001; "A History of Birth Control Methods", Planned Parenthood Report, 2012.)