{"product_id":"principia-rn-03-retinol-serum","title":"Principia RN-0.3 Retinol Serum 0.3% + Vitamin E 0.5% for Fine Line \u0026 Firmness Care, 1.01 fl oz (30 mL)","description":"\u003cstyle\u003e\n  .mkpbr-adeus {\n    --mkpbr-orange: #ff6b4a;\n    --mkpbr-orange-dark: #e85a37;\n    --mkpbr-black: #111111;\n    --mkpbr-muted: #666666;\n    --mkpbr-soft: #faf9f7;\n    --mkpbr-line: #ececec;\n    --mkpbr-white: #ffffff;\n    color: var(--mkpbr-black);\n    font-family: inherit;\n    font-size: 16px;\n    line-height: 1.65;\n  }\n\n  .mkpbr-adeus *,\n  .mkpbr-adeus *::before,\n  .mkpbr-adeus *::after {\n    box-sizing: border-box;\n  }\n\n  .mkpbr-adeus h2,\n  .mkpbr-adeus h3,\n  .mkpbr-adeus p {\n    margin-top: 0;\n  }\n\n  .mkpbr-adeus h2 {\n    margin-bottom: 14px;\n    color: var(--mkpbr-black);\n    font-size: clamp(24px, 4vw, 34px);\n    line-height: 1.2;\n  }\n\n  .mkpbr-adeus h3 {\n    margin-bottom: 8px;\n    color: var(--mkpbr-black);\n    font-size: 18px;\n    line-height: 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{\n    padding: 7px 12px;\n    border: 1px solid var(--mkpbr-line);\n    border-radius: 999px;\n    background: var(--mkpbr-soft);\n    font-size: 14px;\n  }\n\n  .mkpbr-adeus__notice {\n    margin-top: 18px;\n    padding: 16px 18px;\n    border-radius: 12px;\n    background: #fff2ee;\n    color: #552217;\n  }\n\n  .mkpbr-adeus__details {\n    border-top: 1px solid var(--mkpbr-line);\n  }\n\n  .mkpbr-adeus__details details {\n    border-bottom: 1px solid var(--mkpbr-line);\n  }\n\n  .mkpbr-adeus__details summary {\n    position: relative;\n    padding: 18px 42px 18px 0;\n    cursor: pointer;\n    color: var(--mkpbr-black);\n    font-weight: 700;\n    list-style: none;\n  }\n\n  .mkpbr-adeus__details summary::-webkit-details-marker {\n    display: none;\n  }\n\n  .mkpbr-adeus__details summary::after {\n    position: absolute;\n    top: 50%;\n    right: 4px;\n    color: var(--mkpbr-orange);\n    content: \"+\";\n    font-size: 24px;\n    font-weight: 500;\n    transform: translateY(-50%);\n  }\n\n  .mkpbr-adeus__details details[open] summary::after {\n    content: \"\\2212\";\n  }\n\n  .mkpbr-adeus__details-body {\n    padding: 0 36px 18px 0;\n    color: var(--mkpbr-muted);\n  }\n\n  .mkpbr-adeus__details-body p:last-child {\n    margin-bottom: 0;\n  }\n\n  .mkpbr-adeus__disclaimer {\n    margin-top: 28px;\n    padding: 18px;\n    border: 1px solid var(--mkpbr-line);\n    border-radius: 12px;\n    color: var(--mkpbr-muted);\n    font-size: 13px;\n  }\n\n  @media (max-width: 749px) {\n    .mkpbr-adeus__grid,\n    .mkpbr-adeus__steps {\n      grid-template-columns: 1fr;\n    }\n\n    .mkpbr-adeus__section {\n      padding: 28px 0;\n    }\n  }\n\u003c\/style\u003e\n\u003cdiv class=\"mkpbr-adeus\"\u003e\n\u003csection class=\"mkpbr-adeus__intro\"\u003e\n\u003ch2\u003ePrincipia RN-0.3\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003ePrincipia RN-0.3 \u003c\/strong\u003eis a Brazilian dermocosmetics night serum designed for a refined, results-focused routine—supporting the look of smoother texture, improved radiance, and visibly softened fine lines over time. With 0.3% retinol paired with 0.5% vitamin E, it brings an elegant balance of renewal and antioxidant support, making it a strong fit for customers who want a high-performance anti-aging step that still feels modern, minimal, and easy to integrate.\u003cbr\u003e\u003cbr\u003eThis serum is ideal for international customers, salon retail shelves, and resellers seeking a globally recognized active with clear concentration and a straightforward, professional story.\u003c\/p\u003e\n\u003c\/section\u003e\n\u003csection class=\"mkpbr-adeus__section\"\u003e\n\u003ch2 class=\"mkpbr-adeus__section-title\"\u003eWhy you’ll love it\u003c\/h2\u003e\n\n\u003cdiv class=\"mkpbr-adeus__grid\"\u003e\n\u003cdiv class=\"mkpbr-adeus__card\"\u003e\n\u003ch3\u003eFine line appearance care\u003c\/h3\u003e\n\u003cp\u003eHelps soften the look of fine lines and expression lines with consistent use.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"mkpbr-adeus__card\"\u003e\n\u003ch3\u003eFirmness + elasticity appearance\u003c\/h3\u003e\n\u003cp\u003eHelps improve the look of firmness and elasticity over time.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"mkpbr-adeus__card\"\u003e\n\u003ch3\u003eRadiance support\u003c\/h3\u003e\n\u003cp\u003eHelps enhance the look of glow for a fresher, more luminous finish.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"mkpbr-adeus__card\"\u003e\n\u003ch3\u003eTexture refinement\u003c\/h3\u003e\n\u003cp\u003eHelps improve the look of uneven texture for a smoother surface appearance.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"mkpbr-adeus__card\"\u003e\n\u003ch3\u003eTone uniformity support\u003c\/h3\u003e\n\u003cp\u003eHelps refine the look of uneven tone and discoloration.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"mkpbr-adeus__card\"\u003e\n\u003ch3\u003ePore appearance support\u003c\/h3\u003e\n\u003cp\u003eHelps reduce the look of enlarged pores as texture looks more refined.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"mkpbr-adeus__card\"\u003e\n\u003ch3\u003eDermatologically tested (brand-reported)\u003c\/h3\u003e\n\u003cp\u003eThe brand reports irritation and sensitization testing, plus hypoallergenic \/ non-photoirritating evaluation.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/section\u003e\n\u003csection class=\"mkpbr-adeus__section\"\u003e\n\u003ch2 class=\"mkpbr-adeus__section-title\"\u003eHow to use\u003c\/h2\u003e\n\n\u003cp\u003eUse daily, only at night. Apply on clean, dry skin before creams. Dispense a few drops onto fingertips (avoid touching the dropper to skin) and spread gently over the face, excluding the eye area.\u003cbr\u003eDuring the first week, use small amounts on alternate nights. Wear broad-spectrum sunscreen daily and avoid sun exposure without protection.\u003cbr\u003e\u003cbr\u003eIn a 60-day perceived efficacy study, participants reported improvements in: glow (100%), fine lines (97%), wrinkles appearance (97%), texture (97%), tone (97%), firmness (87%), and elasticity (87%). The brand also reports instrumental measurements showing variation in firmness and elasticity parameters over 60 days, plus comedogenicity\/acnegenicity evaluation. Results may vary.\u003c\/p\u003e\n\u003c\/section\u003e\n\u003csection class=\"mkpbr-adeus__section\"\u003e\n\u003ch2 class=\"mkpbr-adeus__section-title\"\u003eProduct highlights\u003c\/h2\u003e\n\u003cdiv class=\"mkpbr-adeus__tags\"\u003e\n\u003cspan class=\"mkpbr-adeus__tag\"\u003eRetinol (0.3%): A vitamin A derivative whose molecules can penetrate deeper layers of the skin. Retinol is widely used to support antioxidant activity and to promote collagen- and elastin-related pathways that help improve the look of fine lines, firmness, elasticity, and radiance. It also supports surface renewal, helping refine the look of texture and uneven tone over time.\u003c\/span\u003e \u003cspan class=\"mkpbr-adeus__tag\"\u003eVitamin E (0.5%): An antioxidant naturally found in foods like nuts, spinach, and olive oil. In skincare, vitamin E helps neutralize free radicals and is associated with photoprotective support, helping reduce the visible effects of sun-related stress when paired with daily sunscreen.\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"mkpbr-adeus__notice\"\u003e\n\u003cstrong\u003eAllergen warnings \/ cautions:\u003c\/strong\u003e For external use only. Do not apply on irritated, broken, or compromised skin. Avoid contact with eyes; do not apply in the eye area. If contact occurs, rinse thoroughly. Retinol may cause temporary dryness, redness, or peeling; start slowly (alternate nights for the first week). Use broad-spectrum sunscreen daily and avoid sun exposure without protection. If pregnant or breastfeeding, consult a physician before use. Keep out of reach of children. Do not use on children. According to the brand, the formula is free from parabens, petrolatum, sulfates, silicones, fragrance, dyes, and gluten. Principia is a Brazilian dermocosmetics brand founded in 2020 in São Paulo with a clear mission: democratize high-performance skincare through science-backed formulas, radical ingredient transparency, and fair, accessible positioning. Instead of relying on hype, Principia focuses on what matters most for results-driven routines— active ingredients at disclosed percentages, straightforward formulations, and a minimalist, clinical aesthetic designed for everyday use.\u003c\/div\u003e\n\u003c\/section\u003e\n\u003csection class=\"mkpbr-adeus__section\"\u003e\n\u003ch2 class=\"mkpbr-adeus__section-title\"\u003eProduct information\u003c\/h2\u003e\n\u003cdiv class=\"mkpbr-adeus__details\"\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWhen should I use Principia RN-0.3?\u003c\/summary\u003e\n\u003cdiv class=\"mkpbr-adeus__details-body\"\u003e\n\u003cp\u003eUse it at night only, on clean, dry skin, before moisturizer. Always wear sunscreen during the day.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eHow do I introduce retinol if I’m new to it?\u003c\/summary\u003e\n\u003cdiv class=\"mkpbr-adeus__details-body\"\u003e\n\u003cp\u003eStart with small amounts on alternate nights for the first week, then increase to nightly use as tolerated.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eCan I apply this retinol serum around my eyes?\u003c\/summary\u003e\n\u003cdiv class=\"mkpbr-adeus__details-body\"\u003e\n\u003cp\u003eNo. The brand advises avoiding the eye area.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eCan I use RN-0.3 with other active ingredients?\u003c\/summary\u003e\n\u003cdiv class=\"mkpbr-adeus__details-body\"\u003e\n\u003cp\u003eMany routines combine actives, but to reduce irritation, avoid layering multiple strong exfoliants in the same night. Consider alternating nights when using acids.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eIs Principia cruelty-free?\u003c\/summary\u003e\n\u003cdiv class=\"mkpbr-adeus__details-body\"\u003e\n\u003cp\u003eThe brand states it does not test on animals.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003c\/div\u003e\n\u003c\/section\u003e\n\u003cdiv class=\"mkpbr-adeus__disclaimer\"\u003e\n\u003cstrong\u003eDisclaimer:\u003c\/strong\u003e For external use only. Patch test before use and discontinue use if irritation occurs. Individual results may vary. Product packaging may be labeled in Portuguese. Our Brazilian-brand products are sourced in Brazil and are regularized with ANVISA (Agência Nacional de Vigilância Sanitária), Brazil's national health authority, under the applicable regulatory framework for each product category. ANVISA regularization applies to the Brazilian market and is not equivalent to U.S. FDA approval. See our full \u003ca href=\"\/en-gr\/pages\/disclaimers\"\u003eDisclaimers \u0026amp; Important Information\u003c\/a\u003e.\u003c\/div\u003e\n\u003c\/div\u003e","brand":"Principia","offers":[{"title":"Default Title","offer_id":52626387042620,"sku":"MKPBR2024-1974","price":23.28,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0090\/2840\/3278\/files\/principia-rn-0-3-retinol-serum-0-3-percent-vitamin-e-0-5-percent-1-01-fl-oz-30-ml-front-bottle-buy-now-at-mkpbr-com-worldwide-shipping_d4e6d701-85aa-476c-adec-9ac1d721d8fd.png?v=1784527722","url":"https:\/\/mkpbr.com\/en-gr\/products\/principia-rn-03-retinol-serum","provider":"MKPBR - Shine Like a Brazilian","version":"1.0","type":"link"}