Short answer. No. Article 1890 of the Civil Code says that if an agent is authorized to lend money at interest, the agent cannot borrow it without the principal's consent. An authority to lend on behalf of another does not carry with it permission to take the funds for yourself.
What the law says
If he has been authorized to lend money at interest, he cannot borrow it without the consent of the principal.
Civil Code, Article 1890 — Agent as Lender or Borrower. Read the full provision →
The two rules in Article 1890
Article 1890 sets out a pair of rules that look symmetrical but operate differently. The first: if an agent is empowered to borrow money for the principal, the agent may lend their own money at the current rate of interest rather than going to a third party. The second: if an agent is empowered to lend the principal's money at interest, the agent "cannot borrow it without the consent of the principal." The authority to lend does not flip into permission to borrow. The directions of the agency relationship are not interchangeable.
Why the law draws this line
An agent authorized to lend money holds the principal's funds in a fiduciary capacity. Using those funds for the agent's own benefit creates a direct conflict of interest: the agent is both the custodian of the money and the party who would benefit from taking it. The law removes any ambiguity by requiring explicit consent before this can happen. Without that consent, the transaction is unauthorized regardless of the agent's intention to repay.
What happens if the agent borrows without consent
A borrowing made without the principal's consent is an unauthorized act. The principal did not agree to lend to the agent, and the agency relationship does not supply that agreement by implication. The principal may demand return of the funds and may have a claim for any resulting loss, including foregone interest that a legitimate third-party loan would have generated. The agent's liability is not limited to the principal amount — the agent may owe compensation for the full harm caused by the unauthorized use.
Getting consent properly
If you are an agent who genuinely needs to use funds you are authorized to lend, the right path is to get the principal's explicit consent before the transaction, not after. The consent should ideally be in writing and specify the amount, the rate of interest (if any), and the repayment terms. This converts what would otherwise be an unauthorized borrowing into a properly authorized transaction and protects both you and the principal. Acting first and asking for ratification later is far riskier and may not cure the original problem.