Joaquin “El Chapo” Guzman may be a hardened criminal — but he apparently harbored a soft spot that led him to seek treatment while on the lam.

The diminutive drug lord underwent male-enhancement surgery at a Tijuana hospital, where he received a testicular implant to improve blood circulation in his manhood, Reforma newspaper reported.

The procedure — which usually requires general anesthesia — could not have been performed in the mountains of Sinaloa, where he was hiding, Mexican journalist Carlos Loret told the site SinEmbargo.

Authorities recovered injectable testosterone, anti-inflammatories and a prescription for sexual-performance drugs in the home where he was captured Jan. 8, according to the report.

The surgery reportedly was performed after Guzman met up with Sean Penn and actress Kate del Castillo.