Tretinoin has long been used off label for antiaging treatments but has only recently shown efficacy for facial pores. In one study, 60 women who had previously sought antiaging procedures were treated with tretinoin cream 0.025% once daily and no other antiaging products or procedures for 90 days.11 Facial pore evaluations were determined by a modified dermatoscope with a polarized analyzer for clinical scoring using a photonumeric scale. Patients improved from a baseline average score of 3.2 in facial pores to a posttreatment average score of 2.0 (P<.05) at day 84. This improvement was sustained from day 28 of treatment and corresponded to patient self-perception. Adverse events included xerosis, desquamation, burning, and erythema, which led to 3 premature discontinuations.11
Various chemical peel formulations are used in skin rejuvenation and have shown application in enlarged facial pores. Chemical peels act at the epidermal or dermal level to induce temporary breakdown and regeneration of healthier cells and improved skin matrix.12 Twenty-two Japanese women applied glycolic acid (30% solution) every 2 weeks for a total of 5 treatments and exhibited reduced appearance of conspicuous, open, and dark pores, defined by surface area and shading as determined through dermatoscopic and software analysis, with mean improvement rates of 34.6%, 11%, and 34.3%, respectively. More than 70% of participants exhibited improvement in enlarged facial pores.13 A study involving a 40% glycolic acid and vitamin C formulation demonstrated significant improvement in facial pores (28.3%; P<.001).14
The newest topical therapies studied for use in minimizing facial pilosebaceous openings are natural plant-derived copper chlorophyllin complex sodium salt (CHLcu) and tetra-hydro-jasmonic acid (LR2412). Clinical trials of these botanicals are limited with small sample sizes but are included here as novel treatments requiring further investigation.
Chlorophyllin copper complex sodium salt is derived from chlorophyll, a green pigment found in plants, and has been investigated as a topical gel in liposomal dispersions for application in photodamaged and aged skin. Chlorophyllin copper complex sodium salt exerts in vitro hyaluronidase inhibitory activity to maintain hyaluronic acid in the extracellular matrix and counteract the structural breakdown of cutaneous aging.15 Two small single-center pilot trials enrolled 10 participants each in a 3-week study of CHLcu 0.1% twice daily and an 8-week study of CHLcu 0.066% twice daily.16,17 After 3 weeks, patients treated with CHLcu 0.1% exhibited a 22.2% improvement in facial pores by clinical assessment grading, though this improvement was not significant on software imaging analysis. Patients improved the most on parameters of facial seborrhea by clinical assessment.16 After 8 weeks, patients treated with CHLcu 0.066% exhibited 25.3% improvement in facial pores by clinical assessment grading.17 Treatments were reported to be well tolerated without noted adverse events in both studies.
Tetra-hydro-jasmonic acid is an analogue of jasmonic acid, a plant hormone derived from linoleic acid. Due to its favorable safety profile and bioavailability, penetration into epidermal and dermal layers, and potential effects in rejuvenating desquamation, LR2412 is currently being assessed for treatment of skin wrinkles, texture, and pores.18 Its effect is thought to relate to stimulation of laminin-5, collagen IV, and fibrillin deposition at the dermoepidermal junction.19 In an open-label trial of a topical preparation of LR2412, 15 participants were treated twice daily for 6 weeks and assessed through investigator clinical assessment scoring.20 Investigator scoring of pores improved by 25.2% from baseline (P<.05) after 6 weeks of treatment. Improvement in pores was seen as early as days 1 and 3. No serious adverse events were reported, though 2 participants developed acne on follow-up.20
Tetra-hydro-jasmonic acid also is formulated with retinol (retinol 0.2%/LR2412 2.0%) and demonstrated cosmetic efficacy in a noninferiority trial with tretinoin cream 0.025%.11 Sixty patients each were randomized to retinol/LR2412 or tretinoin at bedtime and treated for 90 days. At day 84, participants in the retinol/LR2412 group exhibited an improvement in investigator clinical assessment scoring from a baseline of 3.6 to 2.5 (P<.05). There were no significant differences in investigator-assessed efficacy between the treatment arms. Participants reported similar or better results and fewer side effects with retinol/LR2412 on self-questionnaires. Eight participants treated with retinol/LR2412 and 15 participants treated with tretinoin reported various incidences of skin irritation, burning, and desquamation.11
The most commonly used oral therapies for enlarged pores are antiandrogens, such as combined oral contraceptives, spironolactone, and cyproterone acetate, which modulate sebum production due to the presence of androgen receptors within sebaceous glands.21 Forty-four white women in an open-label, phase 4 study were treated with combined oral contraceptives containing chlormadinone acetate–ethinyl estradiol for 6 menstrual cycles, with standardized photography taken before and after the treatment period for software analysis. After 6 treatment cycles, 9.1% (4/44) of participants had visibly enlarged pores of the forehead and cheeks compared to 43.2% (19/44) of participants at baseline (P<.0001).22 The effects of other antiandrogens on facial pores have not been studied in this capacity.