The pair were remanded in custody on Wednesday after a court hearing in Lima.
Judge Dilo Huaman said he was handing them over to the country’s prison service so it could decide which jail to send them to.
Yesterday, officials said the women had confessed to investigators they knew there were drugs in their suitcases, despite telling police after they were stopped while trying to board a flight to Spain, on 6 August, that they were innocent.
Ms Reid, 20, from Lenzie, near Glasgow, insisted moments after her arrest at Lima’s Jorge Chavez Airport that she had no idea she was carrying drugs.
A spokesman for the court in the Lima neighbourhood of Callao, which rejected their bail pleas, said: “Both foreign citizens, although they claimed they had received threats to make them take the drugs, admitted they knew there were drugs in their luggage and didn’t warn the authorities.
“For that reason, and for others relating to flight risk, they were remanded in custody.
“The jail they are sent to will be determined by the prison service after the relevant assessments take place.
“Under article 296 of our penal code, both women could receive a prison sentence of between eight and 15 years.”
The women insisted they had no idea they were carrying drugs after police stopped them as they tried to board an Air Europa flight to Madrid and discovered more than five kilos of cocaine disguised as food products in each of their suitcases.
An officer from anti-drug squad Dirandro, speaking in pigeon English, asked Melissa in a video released by police: “Your know to contain this bag?”
Ms Reid replied: “I was forced to take these bags in my luggage.”
She was asked again: “You know they contained drugs?”
Ms Reid replied: “I did not know that.”
Michaella, wearing a T-shirt with the words La Vie Est Belle, French for “Life is Beautiful”, stared straight ahead and said nothing. The pair are thought to have confessed they knew they had been given cocaine to take back to Europe during a police interview.
They told investigators they were forced to bring back drugs to Europe by Colombian gangsters wielding guns who threatened them and their families, and followed them every step of the way.
The women were charged with drugs trafficking on Tuesday after being taken to a state prosecutor’s office.
They are expected to be sent to a women’s prison called Ancon 2 about an hour’s drive north of Lima.
The jail, known colloquially as Piedras Gordas 2, was opened in November 2010 to help reduce overcrowding in Lima’s other prisons.
Its four wings are designed to hold nearly 2,500 “non-dangerous” male and female inmates.
Inmates in the women’s and men’s wings sleep eight to a cell and share a toilet hidden behind a low wall.
Hundreds of inmates from other prisons including Santa Monica prison in Chorillos, where it was initially reported the women would be sent, have been transferred to Ancon 2 since its opening. Many have been foreigners serving time for cocaine trafficking.
Yesterday, the women were still being held in a cramped court jail in which they slept on Wednesday night ahead of their first court appearance.
A prison service spokesman said: “They were transferred to the Lima Palace of Justice prison in the early hours of Thursday morning which is where all detainees are taken before the decision on which jail they will be sent to.
“A multi-disciplinary team called the Junta Clasificatoria (Classification Board) will decide what jail they go to.”