Custom Serum
Custom Serum
Product Description
Product overview
A lightweight, AI-personalized face serum custom-formulated for your unique skin concerns. Powered by over 80 diagnostic factors including climate, lifestyle, and skin goals, each bottle features clinically proven actives like hyaluronic acid, ascorbyl glucoside (stable vitamin C), allantoin, and beta-glucan to hydrate, brighten, soothe, and strengthen your skin barrier.
AI-Powered Personalization
Over 15 million possible formula combinations generated from 80+ diagnostic factors including your climate, diet, stress level, and specific skin concerns.
Texture & feel
SENSORYAI-Powered Personalization
Over 15 million possible formula combinations generated from 80+ diagnostic factors including your climate, diet, stress level, and specific skin concerns.
Clinically Tested Results
Dermatologist-approved formula clinically tested on 2,000+ unique skin types. 90% of users reported stronger skin barrier in 4 weeks.
Evolves With You
Review & Refine feature lets you adjust your formula over time as your skin changes with seasons, age, or lifestyle shifts.
Clean & Sustainable
B Corp Certified, Climate Neutral, and ethically sourced ingredients. Recyclable glass bottles with refill program to reduce waste.
Safety & compatibility
SAFEBase formula is free of retinoids, salicylic acid, and hydroquinone. However, since each formula is custom, some may include bakuchiol or botanical extracts. Consult your OB-GYN before use and request a pregnancy-safe version through Prose's quiz.
Contains Sphingomonas Ferment Extract (a ferment) and Polyglyceryl-4 Caprate, which may feed malassezia yeast. Not recommended for fungal acne-prone skin.
Rated 1/5 on the comedogenic scale. Oil-free, silicone-free formula with non-pore-clogging humectants like glycerin and sodium hyaluronate.
Free of common irritants like harsh alcohols, sulfates, parabens, and phthalates. Fragrance-free option available. Dermatologist-tested on sensitive skin.
Uses stable ascorbyl glucoside (not pure L-ascorbic acid), so it pairs well with retinol, AHAs, and BHAs without causing irritation or oxidation.
Since every formula is unique, do a patch test on your inner wrist for 24 hours before full-face application, especially if you have reactive or allergy-prone skin.
Ingredient breakdown
INGREDIENTSSodium Hyaluronate ~1–2%Proven
The salt form of hyaluronic acid, a naturally occurring molecule in skin that holds up to 1,000x its weight in water. Provides deep hydration and plumps the skin to reduce the appearance of fine lines.
- Function: Humectant that draws moisture into the skin and improves elasticity
- Research: Extensively studied; proven to reduce wrinkle depth and improve skin hydration within 2–4 weeks of consistent use
- Molecular size: Low molecular weight form penetrates deeper skin layers for lasting hydration
Ascorbyl Glucoside ~2%Promising
A highly stable vitamin C derivative that converts to pure ascorbic acid after skin absorption. Provides antioxidant protection, supports collagen synthesis, and helps fade hyperpigmentation without the instability issues of pure vitamin C.
- Stability: Water-soluble and highly stable, unlike pure L-ascorbic acid which oxidizes quickly
- Conversion: In-vitro studies confirm it converts to active vitamin C once absorbed into skin
- Benefits: Antioxidant protection, collagen boosting, and pigmentation fading in lab studies
Allantoin ~0.5–1%Proven
A soothing, skin-softening ingredient derived from the comfrey plant (produced synthetically for purity). Promotes cell renewal, calms irritation, and supports wound healing.
- Function: Skin protectant and soothing agent that promotes healthy cell turnover
- Research: Well-established ingredient recognized by the FDA as an effective skin protectant
- Synergy: Often paired with active ingredients to buffer potential irritation
Beta-Glucan ~0.1–0.5%Proven
A polysaccharide derived from yeast, oats, or mushrooms that strengthens the skin barrier, soothes redness, and provides deep hydration. Excellent for sensitive and compromised skin.
- Function: Anti-inflammatory, antioxidant, and wound-healing properties
- Research: Studies show it penetrates the epidermis and stimulates collagen synthesis while calming inflammation
- Barrier support: Helps repair and reinforce the skin's natural protective barrier
Tetrapeptide-30 TracePromising
A synthetic peptide that helps inhibit melanin production by reducing tyrosinase activity. Targets uneven skin tone and dark spots for a more uniform complexion.
- Function: Melanin-inhibiting peptide for brightening and evening skin tone
- Research: In-vitro studies show effective reduction of melanin synthesis; gentle alternative to hydroquinone
Glycerin & Propanediol ~5–8%Proven
Two powerhouse humectants that form the hydrating backbone of this serum. Glycerin (comedogenicity: 0) is naturally found in skin and has been shown to be more effective than HA as a humectant. Propanediol is a corn-derived moisturizer that also enhances ingredient absorption.
- Glycerin: A 2016 study found it outperforms both AHAs and HA as a humectant; also has antimicrobial properties
- Propanediol: Ecocert-approved, sustainably derived from corn sugar; boosts preservative efficacy
20+ ingredients (varies by formula)
Water, Propanediol, Glycerin, Polyglyceryl-4 Caprate, Ascorbyl Glucoside, Sodium Hyaluronate, Allantoin, Ethylhexylglycerin, Polyacrylate Crosspolymer-6, Sodium Citrate, Potassium Hydroxide, Citric Acid, Trisodium Ethylenediamine Disuccinate, Sodium Anisate, Mangifera Indica (Mango) Leaf Extract, Sphingomonas Ferment Extract, Beta-Glucan, Xanthan Gum, Sorbic Acid, Benzoic Acid, Algin, Tetrapeptide-30.
Note: This is one example formulation. Your custom formula may include different or additional ingredients such as Bakuchiol, Hydrolyzed Rhodophyceae Extract, or Polylysine depending on your consultation results.
Where it fits in your routine
ROUTINEApply after cleansing (and toner if used) on damp skin. Follow with your Prose Custom Moisturizer. Use AM and PM for best results.
How to use
HOW TO USECleanse & Prep
Wash your face with Prose Custom Cleanser or your preferred cleanser. Leave skin slightly damp — sodium hyaluronate works best on moist skin.
Apply Serum
Dispense 3–4 drops onto your palm using the glass dropper. Gently pat and press the serum onto your face and neck — avoid rubbing.
Wait & Absorb
Allow 30–60 seconds for the serum to fully absorb before applying the next step. Skin should feel smooth and slightly tacky, not wet.
Moisturize & Protect
Follow with Prose Custom Moisturizer to seal in actives. In the morning, always finish with SPF 30+ sunscreen, especially when using vitamin C.
Who is it for?
WHOPerfect for you if:
- You want a skincare routine specifically tailored to your unique concerns
- You struggle with dullness, uneven tone, or early signs of aging
- You prefer clean, vegan formulas without silicones or parabens
- You value sustainability (B Corp, recyclable glass, refill program)
- You like the idea of a formula that evolves with your skin over time
- You have sensitive skin and need a gentle, fragrance-free option
Consider alternatives if:
- You have active fungal acne (formula contains fermented ingredients)
- You want high-potency pure vitamin C (15–20% L-ascorbic acid)
- You need prescription-strength actives (retinoids, tretinoin)
- You prefer to see exact ingredient percentages before buying
- You want immediate, off-the-shelf availability (Prose takes ~2 weeks to ship)
- You are on a tight budget — at $64 per 30ml, the cost per ml is high
Skin type compatibility
SKIN TYPESLightweight, milky texture absorbs without heaviness. Quiz adjusts formula for oily profiles, but some users report a slightly dewy finish.
Glycerin, propanediol, and hyaluronic acid deliver multi-layer hydration. Formula can be customized with extra moisturizing boosters for very dry skin.
The personalization truly shines here — balances hydration and oil control across different face zones. Top pick for combination skin.
Fragrance-free option available. Allantoin and beta-glucan soothe irritation. Patch test recommended — some users with very reactive skin reported redness.
Low comedogenic rating (1/5) and no oils, but contains a ferment extract. OK for hormonal or bacterial acne; not suitable for fungal acne.
Results timeline
WEEKS 6–8Immediate Hydration Boost
Skin feels softer, smoother, and more hydrated from the first application. Hyaluronic acid and glycerin begin drawing moisture into the skin.
85% noticed improved hydrationTexture Improvement & Calming
Allantoin and beta-glucan work to soothe redness and promote gentle cell turnover. Skin texture starts to feel more refined and even.
72% noticed smoother textureVisible Glow & Barrier Strength
Ascorbyl glucoside delivers antioxidant brightening. Clinical testing showed 90% of users reported a stronger skin barrier and visible glow at this point.
90% reported stronger barrierTone Evening & Fine Line Reduction
Tetrapeptide-30 and vitamin C work synergistically to fade dark spots and even skin tone. Fine lines appear less pronounced with consistent use.
82% noticed more even complexionRatings by platform
1K+ REVIEWSPros & cons
BALANCEDPraised
- Truly personalized — formula adapts to your climate, lifestyle, and skin concerns
- Clean ingredient list: vegan, cruelty-free, paraben-free, silicone-free
- Review & Refine lets you adjust and improve your formula over time
- Eco-friendly recyclable glass packaging with refill options
- Noticeable hydration improvement within the first week for most users
- B Corp and Climate Neutral certifications back up sustainability claims
- 30-day satisfaction guarantee with free remake or refund
Criticized
- Expensive at $64 for 30ml ($2.13/ml) — premium pricing
- Shipping takes 1–2 weeks since products are made to order
- Exact ingredient percentages not disclosed for proprietary reasons
- Subscription management can be confusing; auto-renewal surprises
- Not fungal acne safe due to ferment extract
- Some reviewers found the serum less impressive than the cleanser or moisturizer
- Limited availability — only through Prose.com, not in stores
Budget-friendly alternatives (dupes)
DUPESOffers multi-molecular weight hyaluronic acid and vitamin B5 for deep hydration. Lacks the vitamin C derivative, peptides, and personalization of Prose, but delivers excellent core hydration at a fraction of the price.
Contains 10% pure L-ascorbic acid (more potent than ascorbyl glucoside), hyaluronic acid, and ceramides. Not personalized but offers stronger vitamin C brightening at a drugstore price point.
Features a multi-vitamin C complex including ascorbyl glucoside (same derivative as Prose) plus additional forms. Also includes hyaluronic acid and allantoin. Strong overlap at a much lower price — just without the customization.
Comparison with competitors
SIDE-BY-SIDEPROVEN Skincare (3-Step Set)
Curology Custom Formula
SkinCeuticals Custom D.O.S.E.
Storage & shelf life
6 MONTHS6 months after opening. Each bottle includes a best-by date printed on the label since formulas are made fresh to order.
Store in a cool, dry place away from direct sunlight. No refrigeration required, but avoid high heat and humidity to preserve the vitamin C derivative.
Dark green glass bottle with glass dropper. Recyclable and refillable — keep your dropper for future refill orders to reduce waste.
Yes — 30ml is under the 100ml TSA carry-on limit. Glass bottle is sturdy but wrap carefully to prevent breakage.
Frequently asked questions
FAQIt depends on your specific formula. The base ingredients (hyaluronic acid, glycerin, allantoin) are generally considered safe during pregnancy. However, some custom formulations may include bakuchiol or botanical extracts that lack extensive pregnancy safety data. Prose does not use retinoids, salicylic acid, or hydroquinone — the most commonly flagged pregnancy-unsafe ingredients. We recommend consulting your OB-GYN and noting in Prose's quiz that you are pregnant or breastfeeding so they can adjust your formula accordingly.
No, Prose Custom Serum is generally not considered fungal acne safe. The formula contains Sphingomonas Ferment Extract, a fermented ingredient that can feed malassezia yeast. Additionally, Polyglyceryl-4 Caprate may be problematic for some fungal acne sufferers. If you have active fungal acne, consider alternatives like The Ordinary Hyaluronic Acid 2% + B5 or other minimal, ferment-free serums.
Yes! Prose Custom Serum uses ascorbyl glucoside, a stable vitamin C derivative that plays well with retinol, AHAs (glycolic acid, lactic acid), and BHAs (salicylic acid). Unlike pure L-ascorbic acid, it does not cause pH conflicts with other actives. Apply the serum first, let it absorb, then layer your retinol or acid treatment. If your skin is sensitive, introduce layering gradually and consider alternating actives (vitamin C in AM, retinol in PM).
Prose Custom Serum is designed for all skin types since each formula is personalized. It performs best for dry, combination, and normal skin thanks to its strong hydrating base of glycerin, propanediol, and hyaluronic acid. Oily skin types may find it slightly dewy. Sensitive skin benefits from the fragrance-free option and soothing allantoin. However, those with active fungal acne should avoid it due to fermented ingredients.
Most users notice improved hydration and softer skin within the first week. Texture improvements and reduced redness typically appear around weeks 2–3. The brand's clinical testing showed that 90% of participants reported a stronger, more glowing skin barrier after 4 weeks of twice-daily use. More significant results like faded dark spots and reduced fine lines generally require 6–8 weeks of consistent use.
Apply it as step 3 in your routine: after cleansing and toner, but before moisturizer and sunscreen. For best results, apply to slightly damp skin so the hyaluronic acid can bind moisture effectively. Use 3–4 drops, pat gently into face and neck, then follow with Prose Custom Moisturizer. Use both morning and evening.
Prose Custom Serum has a comedogenic rating of 1 out of 5, meaning it has a very low risk of clogging pores. The formula is oil-free, silicone-free, and mineral oil-free. Key humectants like glycerin (comedogenic rating: 0) and sodium hyaluronate are non-pore-clogging. The brand specifically states their formulations are "free from comedogenic ingredients." However, since each formula is custom, always check your specific ingredient list if you are very acne-prone.
Prose Custom Serum has a PAO (Period After Opening) of 6 months. Since each bottle is made fresh to order, it also includes a best-by date printed directly on the label. Store in a cool, dry place away from direct sunlight. The dark glass bottle helps protect the ascorbyl glucoside from light degradation. With twice-daily use, a 30ml bottle typically lasts about 6–8 weeks.
Verdict: Prose Custom Serum delivers a genuinely personalized skincare experience backed by clean ingredients and thoughtful formulation. The hydrating base of hyaluronic acid, glycerin, and allantoin works well for most skin types, and the AI-driven customization sets it apart from one-size-fits-all competitors. However, the premium price ($64 for 30ml), 2-week shipping wait, and undisclosed ingredient percentages may give some buyers pause. It earns top marks for sustainability, ethics, and the ability to refine your formula over time — but falls short for those with fungal acne or those seeking high-potency actives. Best suited for anyone who values a tailored approach to skincare and is willing to invest in a formula that evolves with their skin.
Product Overview
Quick product notes are a great way to check if a product is free from commonly avoided ingredients by skincare enthusiasts. These preferences come about for different reasons depending on the ingredient such as personal experiences, sensitivities, health preferences & etc.
Just because a product is not free from a common preference does not mean it's a bad product! You can make a personal decision whether or not you want to use a product that contains these ingredients or not - click the labels of the preference to read more about them.
Quick Product Notes
Ever used a product that promised a certain effect but provided no results? It might not have contained any notable ingredients that could have been responsible for that promised effect. It doesn't matter what the marketing or packaging «promises» it can do, if it doesn't contain anything that can help - then the likelihood of it helping is low.
We help you identify key notable ingredients that have been shown to help with effects such as acne-fighting, brightening, UV-protection, wound healing & anti-aging to help you achieve your skincare goals smarter. Please note that different notable ingredients have varying levels of research behind them, some are extremely well proven yet some have mixed research in their efficacy.
Just because a product doesn't contain any notable ingredients doesn't mean it's bad. And a product with notable ingredients (or even many) doesn't necessarily guarantee the efficacy of the product performing these effects either. There are other factors such as ingredient quality, concentration and formulation that will ultimately determine this.
Be smart and use this as just a starting point for you to make more informed and smarter choices and compare it with reviews to see if the product is right for you
Notable Effects & Ingredients
Why are some products great for some people and horrible for others? Well everyone has different skin types and different reactions to the same ingredients.
We've identified a range of ingredients that are commonly regarded as potentially good or bad for those with Dry, Oily/Acne-Prone or Sensitive skin.
A product that contains good or bad ingredients for your skin type doesn't always flat out make the entire product good or bad for your skin. There are other factors such as ingredient quality, concentration and formulation that will ultimately determine your skins reaction.
One of the best ways to use this section is to troubleshoot products you've had bad experiences with in the past. Check if it contains any of the marked ingredients to point out suspect ingredients to avoid in the future!
Ingredients Related to Skin Types
Ingredient Safety Breakdown refers to the percentage % of ingredients in different risk categories as classified by EWG (Environment Working Group) if they are available. There are almost endless cosmetic ingredients and they are one of the few organisations globally that have assigned ratings to a lot of the more commonly used ingredients which is why we reference them.
EWG is seen by many to be more on the alarmist side in their assignment of health ratings resulting in rating ingredients as riskier than they actually are. We recommend using this a reference point rather than a strict guide of ingredient safety and to always do further research if into ingredients that you may find suspect.
Ingredient Safety Breakdown
Product ingredient list
| EWG | CIR | Ingredient Name & Cosmetic Functions | Notes |
|---|---|---|---|
| 1 |
Water
Solvent, Skin Conditioning
|
|
|
| 2 |
Glycerin
Solvent, Perfuming, Fragrance, Humectant, Viscosity Decreasing Agent, Hair Conditioning, Skin Protecting, Denaturant, Skin Conditioning
|
Promotes Wound Healing
Hydrating
|
|
| 0 |
Polyglyceryl-4 Caprate
Emulsifying
|
|
|
| 1 |
Propanediol
Solvent, Viscosity Controlling, Viscosity Decreasing Agent
|
|
|
| 1 |
Sodium Hyaluronate
Skin Conditioning, Humectant
|
Promotes Wound Healing
Hydrating
|





