Arthrofactin mixture comprising (i) arthrofactin A of formula below: R 1 - D-Leu 1 - D-Asp 2 - D- allo -Thr 3 - D-Leu 4 - D-Leu 5 - D-Ser 6 - L-Leu 7 - D-Ser 8 - L-Ile 9 - L-Ile 10 - L-Asp 11, in which - the hydroxyl group of the D- allo -Thr 3 amino acid residue forms an ester bond with the C-terminal carboxyl group of the L-Asp 11 amino acid residue, and - R 1 represents the group of formula (I') below: where R 1 ' is a saturated alkyl chain of 5 to 8 carbon atoms; and (ii) at least one derivative of arthrofactin A, said derivative being of formula below: R - Xaa 1 - Xaa 2 - Xaa 3 - Xaa 4 - Xaa 5 - Xaa 6 - Xaa 7 - Xaa 8 - Xaa 9 - Xaa 10 - Xaa 11 in which - Xaa 1, Xaa 4, Xaa 5, Xaa 7, Xaa 9 and Xaa 10 each represent, independently, D-Leu, L-Leu, D-Ile or L-Ile, - Xaa 2 and Xaa 11 each represent, independently, D-Asp, L-Asp, D-Glu or L-Glu, - Xaa 3 represents D-Thr, L-Thr, D- allo -Thr or L- allo -Thr, - Xaa 6 and Xaa 8 each represent, independently, D-Ser, L-Ser, D-Gln or L-Gln, - the hydroxyl group of the Xaa 3 amino acid residue forms an ester bond with the C-terminal carboxyl group of the Xaa 11 amino acid residue, and - R represents the group of formula (II') below: where R' is an alkyl chain of 5 to 9 carbon atoms, optionally comprising at least one unsaturation; for use in the treatment of acneic skin. (i) arthrofactin A of formula below: R 1 - D-Leu 1 - D-Asp 2 - D- allo -Thr 3 - D-Leu 4 - D-Leu 5 - D-Ser 6 - L-Leu 7 - D-Ser 8 - L-Ile 9 - L-Ile 10 - L-Asp 11, in which - the hydroxyl group of the D- allo -Thr 3 amino acid residue forms an ester bond with the C-terminal carboxyl group of the L-Asp 11 amino acid residue, and - R 1 represents the group of formula (I') below: where R 1 ' is a saturated alkyl chain of 5 to 8 carbon atoms; and - the hydroxyl group of the D- allo -Thr 3 amino acid residue forms an ester bond with the C-terminal carboxyl group of the L-Asp 11 amino acid residue, and - R 1 represents the group of formula (I') below: where R 1 ' is a saturated alkyl chain of 5 to 8 carbon atoms; and (ii) at least one derivative of arthrofactin A, said derivative being of formula below: R - Xaa 1 - Xaa 2 - Xaa 3 - Xaa 4 - Xaa 5 - Xaa 6 - Xaa 7 - Xaa 8 - Xaa 9 - Xaa 10 - Xaa 11 in which - Xaa 1, Xaa 4, Xaa 5, Xaa 7, Xaa 9 and Xaa 10 each represent, independently, D-Leu, L-Leu, D-Ile or L-Ile, - Xaa 2 and Xaa 11 each represent, independently, D-Asp, L-Asp, D-Glu or L-Glu, - Xaa 3 represents D-Thr, L-Thr, D- allo -Thr or L- allo -Thr, - Xaa 6 and Xaa 8 each represent, independently, D-Ser, L-Ser, D-Gln or L-Gln, - the hydroxyl group of the Xaa 3 amino acid residue forms an ester bond with the C-terminal carboxyl group of the Xaa 11 amino acid residue, and - R represents the group of formula (II') below: where R' is an alkyl chain of 5 to 9 carbon atoms, optionally comprising at least one unsaturation; for use in the treatment of acneic skin. - Xaa 1, Xaa 4, Xaa 5, Xaa 7, Xaa 9 and Xaa 10 each represent, independently, D-Leu, L-Leu, D-Ile or L-Ile, - Xaa 2 and Xaa 11 each represent, independently, D-Asp, L-Asp, D-Glu or L-Glu, - Xaa 3 represents D-Thr, L-Thr, D- allo -Thr or L- allo -Thr, - Xaa 6 and Xaa 8 each represent, independently, D-Ser, L-Ser, D-Gln or L-Gln, - the hydroxyl group of the Xaa 3 amino acid residue forms an ester bond with the C-terminal carboxyl group of the Xaa 11 amino acid residue, and - R represents the group of formula (II') below: where R' is an alkyl chain of 5 to 9 carbon atoms, optionally comprising at least one unsaturation;