Stretch marks are dermal scars of multifactorial etiology, for which several treatments have been proposed. Among these is microneedling (MN), a technique that stimulates collagen production. However, the effects of MA alone and in combination with active agents on the length and area of stretch marks and the thickness of the integumentary system are not well understood, as the literature is scarce. Therefore, the objectives of this study were: To assess the effects of MA alone and in combination with active agents (growth factors, hyaluronic acid, and Hydroxyprolisilane CN®️) on clinical parameters (area and length) of stretch marks and morphological parameters (dermal and hypodermal thickness) of the female integumentary system. The sample was randomized into a control group (G1) that did not receive treatment, G2 that received MN alone, and G3 that received MN combined with active agents. Groups G2 and G3 underwent 3 sessions of the protocol with a 4-week interval. Groups were evaluated at the beginning and 4 months after the start of the protocol. Evaluation of the area and length of stretch marks was performed through photography, dermal and hypodermal thickness was assessed via ultrasonography, and satisfaction levels were measured using the Likert scale.

This study was a randomized clinical trial in blocks with a 1:1 allocation, stratified by weight. The study was duly adapted to resolution 466/12 of the National Health Council on research involving human beings and to the Declaration of Helsinki. The evaluations and treatment protocols were carried out at the Physiotherapy Clinic of a Private Higher Education Institution.. The sample was characterized by convenience and healthy women who met the inclusion criteria were recruited, mainly via social networks. To calculate the sample size, the G-Power software (version 3.1.3; University of Trier, Trier, Germany) was used and the significance level adopted was α = 0.05 and power (1-β) = 0.80. No similar studies were found, so f 0.30 was used as the effect size. Therefore, the minimum number of participants required for the study was estimated at 24 participants. Considering possible losses during the protocol, 26 participants (+10%) were recruited. Randomization was performed by stratifying by weight. The randomization list was kept in opaque and sealed envelopes, ensuring that the allocation was hidden and random and that the therapist responsible for applying the microneedling had contact with the randomization only on the day of the protocol application. In the present study, the sample of 26 participants was divided into three groups. Group one (G1), control, composed of eight people, underwent all the evaluations, but did not receive the microneedling protocol or actives. Group two (G2), composed of nine people, underwent all the proposed evaluations and the isolated microneedling procedure. Group three (G3), composed of nine people, underwent all the proposed evaluations and the microneedling procedure associated with actives. Groups G2 and G3 underwent 3 sessions of the protocol with a 4-week interval. Groups were evaluated at the beginning and 4 months after the start of the protocol. Evaluation of the area and length of stretch marks was performed through photography, dermal and hypodermal thickness was assessed via ultrasonography, and satisfaction levels were measured using the Likert scale.This study adopted the intention-to-treat approach. Therefore, participants who did not attend the scheduled sessions were rescheduled, allowing all sessions planned to be carried out. When the decision was made to withdraw, the data collected up until the end were used for analysis.

Inclusion Criteria:

• Healthy women (self-declaration of no diseases)
• Age between 18 and 35 years
• Presence of striae alba in the gluteal region

Exclusion Criteria:

• Health problems (cardiovascular, neurological, or musculoskeletal impairment)
• History of keloids
• Allergic disorders
• Skin cancer
• Systemic disease
• Diabetes mellitus
• Pregnant women
• Lactating women
• Psoriasis sufferers
• Hypersensitivity
• Use of peels, lasers, or any similar treatment in the last three months or any contraindication for performing microneedling.