A tumble in the peso in May has stoked expectations that Mexico could raise interest rates next month in a bid to defend the currency.
The peso sank as much as 0.9 percent to 18.4510 per dollar, its weakest since February.
The move, announced last week, was part of an assault on speculators who have battered the local currency.
The peso fell 0.2 percent against the dollar in morning trading to 18.315, after hitting a monthly low of 17.962 on Wednesday after the move by the Bank of Mexico.
English16/02/2016
Dollar closes at $19.19 pesos
The peso responded to the fall of an expected agreement between major oil producers.
The peso sank 1.5 percent to 19.2225 per dollar, its lowest since a 1993 revaluation.
Mexican central bank Governor Agustín Carstens said that it is appropriate to maintain current levels of currency intervention due to the collection of shocks facing the peso's exchange rate.
Earlier on Friday, the central bank sold US$200 million in two auctions.
Mexican growth slowed in the fourth quarter due to flat industrial activity.
After a week of controversy the Mexican TV host said that only an idiot would think that the dollar does not affect Mexico's economy.