Trinh Van Vinh and Nguyen Thi Phuong Thanh had been caught using performance-enhancing drugs in 2018 and banned for four years.
Now top lifters Thach Kim Tuan, Hoang Thi Duyen and Vuong Thi Huyen will undergo tests before and after all regional, continental and world tournaments.
The national weightlifting team is currently training at National Sports Training Centers in Hanoi and Saigon after the Tokyo 2020 Olympics qualifiers were postponed due to the Covid-19 outbreak.
The IWF said competitions would restart in the next few months without mentioning an exact time frame.
Do Dinh Khang, deputy director of the elite sports department at the National Sports Administration, said that weightlifters are targeting tickets for the Tokyo Olympics, which has been postponed by a year to July 2021.
The team has high hopes for Tuan in the men's 61 kg, and Duyen and Huyen in women’s 59 kg and 49 kg weight classes.
At the 2020 Rome Weightlifting World Cup in January, Tuan and Duyen each won three gold medals and Huyen grabbed two bronzes.
Weightlifting is a high-risk sport for doping, and around 312 top contestants have their both blood and urine randomly tested before tournaments, according to the IWF.
It recently banned Thai weightlifters from the 2021 SEA Games in Vietnam after many were caught doping at last year’s games in the Philippines.