Cleansing and moisturizing are two of the most fundamental aspects of human hygiene that affect skin health and disease [1]. A cleanser is applied daily to remove dirt, sebum, sweat, and oils from the skin. The most common cleanser formulas on the market today are made up of synthetic detergents called syndets, which have a lower alkaline pH than soaps and hence remove fewer intercellular lipids [1]. The cleansing property involves physical and chemical interactions due to the attributes of the surfactant in the cleanser, which aids in the solubilization of oily materials. Surfactants act as emulsifiers in skin cleansers by lowering the surface tension of the skin [2].

However, regular skin pH disruption due to cleansing can cause severe irritation, particularly in compromised or sensitive skin [1]. Therefore, the choice of cosmetic products for cleansing is vital, as a product with a high surfactant content reduces the natural moisturizing factor and epidermal intercellular lipids of the skin, leading to dermatological problems such as xeroderma and other clinical manifestations [3-5]. It is also necessary for cleanser products to maintain a proper balance between removing dirt and excess skin lipids and maintaining skin hydration [6,7].

As the skin ages naturally (internal factors), its capacity to retain water is significantly reduced, together with a decrease in sebum production, especially in women [8-11]. In addition, external factors such as ultraviolet (UV) radiation, cigarette smoke, and smog may also reduce skin hydration and damage the skin barrier [11,12]. A combination of these changes, owing to internal and external factors, leads to skin dryness that manifests as dullness, uneven skin tone, texture, and the appearance of fine lines and wrinkles [13].

Skin hydration is essential for skin health [14] and sufficient skin hydration levels are required for the skin to maintain normal functional activity and epidermal barrier integrity [15]. Insufficient skin hydration leads to skin dryness, signs of skin aging, and the skin becoming vulnerable to environmental factors [16]. Therefore, facial moisturizers are crucial for healthy skin, as they prevent dehydration by limiting moisture loss and accelerating cell regeneration. This is achieved when the stratum corneum (SC), also known as the horny layer, secures moisture using a surface film of oil [17]. Ideal moisturizers can repair and restore skin barrier and function, mimic the natural moisturizing system of the skin, and increase skin hydration and water content [18].

The Luzstre facial cleanser contains surfactants, such as decyl glucoside and cocamidopropyl betaine. Surfactants or surface-active substances are the main active ingredients in cleansers; they reduce skin surface tension and play an essential role in removing sebum, sweat, dirt, microorganisms, and exfoliated corneal cells from the skin [2,19]. Macadamia seed oil in the cleanser is rich in monounsaturated fatty acids and contains natural antioxidants such as vitamin E (tocotrienol and tocopherol). It can help minimize skin irritation and oxidative stress owing to its antioxidant properties [20]. Moreover, the components of macadamia seed oil are highly comparable to the natural oils of the skin; thus, they can permeate the skin and keep it moisturized and nourished [21]. In addition, sodium hyaluronate, betaine, and squalene in the moisturizer can moisturize the skin, thus reducing skin aging. The moisturizer also contains tocopheryl acetate, a soluble substance of vitamin E. Tocopheryl acetate has emollient, humectant, and antioxidant properties that can fight against free radicals and protect skin against UV light. It also helps reduce the appearance of facial lines and wrinkles [22].

However, the combination of these ingredients in skincare has not been well studied in Malaysia. Thus, this study aimed to evaluate the safety and efficacy of a combination of Luzstre facial cleanser and moisturizer for skin rejuvenation.

Study participants

A total of 34 healthy volunteers were recruited for the study. The inclusion criteria were Malaysian citizens, man and woman, aged 20 to 60 years. Participants taking isotretinoin, immunocompromised patients who had undergone any cosmetic procedures such as laser and light treatment or whitening treatments for the past 3 months, and those who had a history of facial surgery were excluded from the study. Fig. 1 shows a flowchart of the study.

Figure 1. Flow chart illustrating participant enrollment and progress through the study.

Study product

Facial cleanser and moisturizer were provided by Zeyls Clinic.

International Nomenclature of Cosmetic Ingredients (INCI) of the facial cleanser

Ingredients: Aqua, Decyl Glucoside, Sodium Lauroyl Sarcosinate, Cocamidopropyl Hydroxysultaine, Cocamidopropyl Betaine, Glycerin, PPG-2 Hydroxyethyl Cocamide, Sodium Hyaluronate, Polyquaternium-7, Styrene/Acrylate Copolymer, Glycereth-8 Macadamia Seed Oil Esters, Algae Extract, Zinc PCA, Magnesium PCA, Manganese PCA.

INCI of the facial moisturizer

Ingredients: Aqua, Caprylic/Capric Triglyceride, Urea, Glycerin, Methylpropanediol, Isocetyl Stearate, Sodium Hyaluronate, Betaine, Cetyl Alcohol, Squalane, Tocopheryl Acetate, Polyacrylamide, C13-14 Isoparaffin, Laureth-7, Acrylates/C10-30 Alkyl Acrylate Crosspolymer, Triethanolamine, DMDM Hydantoin, Iodopropynyl Butylcarbamate, Parfum, CI 42090.

Study design

This was a one-sided blind, single-arm prospective study with a small sample size (34 healthy volunteers), conducted from September 2022 to January 2023, and was approved by the Joint Research Review and Ethics Committee, MAHSA University (RMC/EC42/2022). The ClinicalTrials.gov identifier is NCT05694429. The sample size was calculated using the G*Power software with a power of 80% and a dropout rate of 20%. Each participant was their own control, as measurements and evaluations were performed before and after product usage for 8 weeks. Before participation, explanations were provided to the participants regarding the study and their rights. They were allowed to withdraw from the study at any time for any reason. The study commenced after informed consent was obtained from all the participants. After the initial skin assessments were conducted, the participants received 2 products, a facial cleanser and a moisturizer, and were instructed to use both products twice a day for 8 weeks. The participants were prohibited from using their usual facial cleanser and moisturizer during the study period. Skin assessments were performed at baseline and at weeks 3 and 8. For facial cleanser efficacy, the participants were required to wash their faces during the baseline visit by following the procedure provided by the researcher for standardization purposes, and skin assessments were conducted before and after they washed their faces. We received the ethical approval to conduct the study from the Ethics Committee. Besides that, signed inform consent was also obtained from the participants.

Outcome measures

The primary outcome measure of this study was the skin parameter assessment, that is, skin hydration, elasticity, wrinkles, sebum, and pores, and safety assessment. A participant satisfaction survey was used as the secondary outcome measure.

Skin hydration, elasticity, wrinkles, sebum, and pore assessment

Participants’ skin hydration, elasticity, wrinkles, sebum, and pores were assessed using Janus III (PSI Co. Ltd., Seoul, Korea), a facial skin analysis system, at baseline, week 3, and week 8. Images captured using Janus III were recorded and analyzed. The assessment was conducted at a room temperature of 24°C to 26°C and with relative humidity of 45% or less.

Participant satisfaction survey

The participants’ satisfaction with the products was assessed using a questionnaire administered after the study completed, at week 8.

Safety assessment

The safety of the cleanser and moisturizer products was evaluated throughout the study via an adverse event reported by the participants.

Statistical analysis

Statistical analyses were conducted using the SPSS version 20 (IBM Co., Armonk, NY, USA). The results were expressed as mean±standard deviation (SD). The Shapiro–Wilk normality test was conducted on continuous data. The data were analyzed using the paired t-test and Wilcoxon signed-rank test to compare the before and after effects of using a facial cleanser. Repeated measures analysis of variance and Friedman test were used to compare the effect of the combined cleanser and moisturizer at baseline, week 3, and week 8. Statistical significance was set at p<0.05.

Demographic characteristics of participants

A total of 34 participants were enrolled in the study; however, only 27 (79.41%) completed it. Of these, 7 participants discontinued prematurely because they had adverse reactions to the products (3; 8.82%), were unable to attend the last follow-up session (3; 8.82%), or did not follow the study regimen after the baseline skin assessment (1; 2.94%). Of these 7 participants, 2 reported a history of allergies at baseline. Most of the study participants (85.2%) were Malay, and half of the participants (51.9%) were aged 31 to 40 years (Table 1). Almost all study participants (88.9%) did not smoke or vape. Approximately 77.7% of the participants were exposed to sun for 4 hours or less per day, and 74.0% wore sunscreen at least once daily.

Table 1 . Demographic characteristics of participants (n=27).

Characteristics	Number (%)
Gender
Man	6 (22.2)
Woman	21 (77.8)
Age (yr)
20–30	2 (7.4)
31–40	14 (51.9)
41–50	8 (29.6)
>50	3 (11.1)
Race
Malay	23 (85.2)
Chinese	2 (7.4)
Indian	2 (7.4)
Smoking or vaping
Yes	1 (3.7)
No	24 (88.9)
Missing*	2 (7.4)
Duration of sun exposure (h)
<2	13 (48.1)
2–4	8 (29.6)
4–6	5 (18.5)
>6	1 (3.7)
Sunscreen usage (times)
Never	7 (25.9)
1	12 (44.4)
2	6 (22.2)
>3	2 (7.4)

*Missing data..

Effect of facial cleanser on skin pores, sebum, and moisture parameters before and after usage

After using the facial cleanser, the participants’ number of skin pores and sebum levels were significantly reduced (p<0.05) (Table 2). The moisture level also decreased significantly after using the facial cleanser (p<0.05). The difference in facial sebum before and after using the facial cleanser as measured by the Janus III skin analyzer under UV light is shown in Fig. 2.

Table 2 . Comparison of the mean±standard deviation of skin pores, sebum, and moisture of participants before and after using facial cleanser (n=27).

Skin parameters	Before facial cleanser	After facial cleanser
Pore	45.85±6.46	43.56±5.37*
Sebum	150.22±202.90	122.85±183.68*
Moisture	27.52±11.33	24.22±11.40*

Values are presented as mean±standard deviation..

*Significant difference from before facial cleanser application at p<0.05..

Figure 2. Reduction of facial sebum before (A) and after (B) using facial cleanser. The arrows show the reduced area of facial sebum.

Effects of combined facial cleanser and moisturizer use on skin pores, wrinkles, elasticity, moisture, and sebum parameters

After using both a facial cleanser and moisturizer for 8 weeks, the moisture level of the participants improved significantly (p<0.05) compared to the baseline (Table 3). However, there were no significant changes in the participants’ skin pores, wrinkles, elasticity, or sebum levels from baseline to week 8. The difference in facial sebum obtained using the Janus III skin analyzer under UV light between baseline and week 8 is shown in Fig. 3.

Table 3 . Comparison of the mean± standard deviation of skin pores, wrinkles, elasticity, moisture, and sebum of participants at baseline, week 3, and week 8 (n=27).

Skin parameters	Baseline	Week 3	Week 8
Pores	45.85±6.46	45.56±6.03	45.30±6.40
Wrinkles	22.67±7.07	21.81±6.74	21.33±6.77
Elasticity	55.30±13.81	57.26±15.37	53.81±12.81
Moisture	27.52±11.33	34.33±11.68	36.41±15.79*
Sebum	150.22±202.90	135.59±204.66	146.26±230.12

Values are presented as mean±standard deviation..

*Significant difference from baseline at p<0.05..

Figure 3. Facial sebum reduction after using a combination of cleanser and moisturizer at baseline (A) and after 8 weeks (B). The arrows indicate the reduced area of facial sebum.

Participant satisfaction survey

Of the 27 participants, only 23 answered participant satisfaction survey after completing the study. More than 80% of the participants reported that, after using both products, their skin felt hydrated and did not feel itchy (Table 4). Moreover, more than 60% of participants perceived that the products provided a soothing sensation; their skin felt soft, did not feel dry or sticky, and became more radiant. Approximately 86.9% of participants were satisfied with the products.

Table 4 . Participants’ satisfaction about the product.

	Agree (%)	Neutral (%)	Disagree (%)
My skin feels soft	78.3	17.4	4.3
It gives soothing sensation	65.2	26.1	8.7
My skin feels hydrated	82.6	13	4.3
My skin does not feel itch	86.4	4.5	9
My skin does not feel dry	65.2	26.1	8.7
My skin has become more radiant	65.2	30.4	4.3
My skin does not feel sticky	73.9	17.4	8.7
Overall, I’m satisfied with the product	86.9	8.7	4.3

This study supports the idea that regular use of cleansers and moisturizers benefits the skin, especially the face. Luzstre facial cleanser was found to reduce the number of skin pores and sebum of participants directly after washing. The decrease in skin pores in the participants might have been due to a reduction in skin sebum after cleansing. Skin sebum is excreted through skin pores [23], and the number of skin pores can be reduced by decreasing excessive skin sebum production and accumulation [24]. Surfactants are the ingredients in cleansers that remove sweat, dirt, oils, and sebum from the skin [4]. Therefore, the ability of Luzstre facial cleanser to reduce skin sebum may be due to the surfactants present in the cleanser. However, surfactants also reduce the skin moisture after cleansing. They bind to proteins in the SC layer of the skin, causing transient swelling and hyperhydration during cleansing. After cleansing, the SC proteins shrink as water evaporates, causing drying stress [25].

Because cleansers cannot differentiate skin sebum from intercellular lipids, lipids are removed during cleansing [1]. Therefore, moisturizers are designed to replenish skin lipids after cleansing [26-28], and are important for restoring skin hydration. Frequent washing with cleansers may cause skin dryness, after-wash tightness, skin barrier damage, irritation, itching, and erythema [29]. The use of moisturizers is important for overcoming the effects of frequent facial washing. Moisturizers can alleviate dry skin symptoms such as itching and enhance skin appearance [30]. Ideal moisturizers should have emollient properties that make the skin smooth and supple, restore the skin lipid barrier, and be rapidly absorbed to provide immediate and long-term skin hydration [31].

Because Luzstre cleanser affects skin dryness, using Luzstre moisturizer was important to maintain skin hydration. Moisturizers help increase skin hydration, make the skin smooth and soft, improve skin appearance, and deliver active ingredients to the skin surface [1]. The results of this study showed that skin hydration of the participants improved significantly after using the moisturizer for 8 weeks. Using Luzstre moisturizer may replenish the loss of skin hydration after facial cleansing and maintain the participants’ skin hydration. This hydration effect may be due to the essential ingredients of Luzstre moisturizer for skin hydration. These include antioxidants (tocopheryl acetate), humectants, skin-identical ingredients (urea, glycerin, sodium hyaluronate, betaine), and emollients (caprylic/capric triglyceride, isocetyl stearate, cetyl alcohol, Squalane, C13-14 Isoparaffin). However, there is a lack of evidence to determine whether this observed difference is due to the combined use of the cleanser and moisturizer or moisturizer alone.

No significant changes were observed in the skin wrinkles. A possible explanation for this finding is the short duration of the study. It is unrealistic to reverse the process within 12 weeks, as it takes decades to develop wrinkles [32]. Wrinkles are creases or folds that manifest on the face and body when the skin loses its elasticity and the collagen level is reduced over time. Skin wrinkles appear because of natural aging and extrinsic factors such as smoking and UV radiation [33].

In this study, the participants reported high product satisfaction. They felt that their skin became hydrated, smooth, and soft after using the product for 8 weeks.

Limitation of study

This study has a few limitations that must be addressed. First, there was an absence of a control group, potential bias due to the single-arm study design, and existence of confounding factors such as the participants’ daily lifestyle (diet, exercise, smoking, sun exposure, etc.). Second, the small sample size and short study duration are limitations that should be considered. Future studies involving a randomized controlled trial would be beneficial to control for potential bias due to the study design and confounding factors as well as to determine whether the observed effects are specifically due to the use of the Luzstre facial cleanser and moisturizer. In addition, a larger sample size and longer study duration are necessary to improve the validity of the results. A larger sample size could increase the study’s statistical power and improve the generalizability of the findings. A longer follow-up period could provide more insight into the long-term effects of the product on skin health.

Conclusion

Using a combination of the Luzstre facial cleanser and moisturizer for 8 weeks significantly improved the participants’ skin hydration. In addition, using the Luzstre facial cleanser significantly reduced the number of skin pores and sebum after cleansing, resulting in high product satisfaction. These findings suggest that Luzstre facial cleansers and moisturizers should be part of a routine skincare regime, particularly for individuals with sebum and pore problems. This result indicates the need for further research on other skin conditions such as acne, eczema, and psoriasis.

We would like to thank Zeyls Clinic for supporting this study; Amaya Aesthetic Clinic, MAHSA Avenue Kuala Lumpur, for providing the study assessment place; and all participants involved in the study. Suhaila Sujani is from Zeyls Clinic, which sponsored this study.

The authors have nothing to disclose.