Objectives: This experimental study aims to examine the effectsof Tendoflex® and Hypericum perforatum on tendon healing inrat models undergoing iatrogenic Achilles tendon rupture andsimilar surgical treatments. Materials and methods: Eighty Wistar albino rats weighing250 to 350 g were randomly divided into four groups. Group A:Tendoflex® was administered orally as 1 capsule/2.5 kg dailyby gavage. Group B: Hypericum perforatum was administeredorally as 300 mg/kg daily by gavage. Group C: Tendoflex® andHypericum perforatum were co-administered orally by gavage atthe prespecified doses. Group D: No medication was given to thecontrol group. Five rats from each group were sacrificed weekly,and the tissue samples were examined histologically, followed bythe biomechanical tests of the Achilles tendon. Results: In the mechanical testing, pulling forces were superiorin all intervention groups and in all weeks over the controlgroup. In particular, in the early periods (Weeks 1, 2, and 3), themixed group showed the most favorable results, followed by theHypericum perforatum group (p=0.010, p=0.591, and p=0.130,respectively). The most favorable collagen type I and type IIIexpression values were found in the mixed and Hypericumperforatum groups at Weeks 2 and 3, respectively (p=0.025and p=0.018). In the immunohistochemical and Western Blotexaminations, extreme collagen type I and type III expressionwere detected in the mixed and Hypericum perforatum groupsat Weeks 2, 3, and 4. Conclusion: Tensile strength of the Achilles tendon increased byusing Hypericum perforatum and Tendoflex® following ruptureand repair of the Achilles tendon in rats. The combined use ofthese two agents yielded the most favorable mechanical andhistological results, particularly in the early period. This resultmay be related to the higher level of collagen type I and type IIIimmunity in all groups, compared to the control group.