Those who took the medicine - which stops bloodclots from breaking down - were significantly more likely to survive.
"We now have important evidence that the early use of tranexamic acid can save women's lives and ensure more children grow up with a mother," said Haleema Shakur of the London School of Hygiene and Tropical Medicine, which coordinated the trial.
"The need for an operation where you explore why a woman is bleeding can be reduced by a third and there are no side effects. It's really fantastic news for women all over the world."
TXA was invented in the 1960s by a Japanese husband-and-wife research team, Shosuke and Utako Okamoto.
According to the study published in The Lancet, almost all of the deaths from PPH took place in low-and middle-income countries.
"Mothers [in Pakistan] are faced with poverty and our social norms also don't encourage us to visit hospitals or doctors for regular checkups," Sajida Begum, a resident of Sher Garh Mardan in Pakistan's Khyber Pakhtunkhwa province told Al Jazeera.