By: Skin Care Ox

Written By: Diane Elizabeth K. // First Published: 03/13/2020

OSEA Malibu’s Hyaluronic Sea Serum promises to add a boost of hydration to your skin care regimen using the power of hyaluronic acid and sea algae. At $88, it’s definitely at the higher end of the facial serum spectrum. Which begs the question: is the Hyaluronic Sea Serum worth the money? Does it deliver on the claims of adding hydration? Can oily skin types use this serum? Is it good for other skin types? Does it cause breakouts? After reviewing the Hyaluronic Sea Serum for over 30 days, we’ve got some answers to the questions above. During the review period, our team researched every ingredient, trialed the product faithfully, and analyzed real online customer reviews to create this comprehensive review.

Overall, the Hyaluronic Sea Serum did perform well when added to a variety of skin care routines. It has a very lightweight gel consistency that is very “slippy” feeling (making it super easy to spread a little over your whole face). Soon after applying, the serum has a slightly tacky feeling that goes away with further absorption. When layered with other serums and moisturizers, the Hyaluronic Sea serum didn’t add any feeling of heaviness. This serum, however, is not designed to be used alone for hydration (see Product Design & Effectiveness section below for more details). So, if you were looking for a good serum+moisturizer combo, this isn’t your best bet.

Below, you’ll find a complete summary of our in-depth 30 day review of OSEA Malibu’s Hyaluronic Sea Serum. Our reviews are organized into three categories: The Clean Ingredient Score (is the product made with clean ingredients?), Product Design & Effectiveness Score (does the product actually work?), and the Online Customer Review Score (what is everyone else saying?). Combined, this review should provide everything you need to decide if the Hyaluronic Sea Serum is right for you. Enjoy!


Product Name: Hyaluronic Sea Serum

Product Description: A lightweight hyaluronic acid serum made with organic and all natural ingredients. Made with ultra hydrating ingredients such as organic algae and two types of hyaluronic acid for maximum benefit. Size: 2 oz Packaging: Thick frosted glass bottle w/ glass dropper dispenser Consistency: Light Gel Scent: Unscented Samples Available: No

Price: 88

Currency: USD

Availability: InStock

  • Clean Ingredient Score
  • Product Design & Effectiveness Score
  • Online Customer Review Score

Where to Buy?


The Osea Malibu Hyaluronic Sea Serum has earned a Clean Ingredient Score of an “A+” for its cruelty-free, gluten-free, vegan, all-natural, and organic formulation. This hyaluronic acid serum is made with just 11 ingredients including three forms of organic algae for extra nourishment (gigartina skottsbergii extract, macrocystis pyrifera extract, and undaria pinnatifida extract). Other ingredients include two forms of hyaluronic acid (both large and small molecular sizes), Japanese honeysuckle extract, chlorophyll (for pigment), and two natural preservatives. The Hyaluronic Sea Serum lost a few points for its preservative system, potassium sorbate. Potassium sorbate is a naturally-derived food-preservative that has been linked to skin irritation in high concentrations. Osea Malibu uses very low concentrations of potassium sorbate (based on its placement towards the bottom of the ingredient list–indicating low quantity relative to the other ingredients on the list). During our two week review process, the Skin Care Ox team experienced no signs of irritation while reviewing the Hyaluronic Sea Serum.

Clean Ingredient Summary


Top Clean Ingredients

  • Algae Extract: Chlorophyll containing ocean dwelling organisms. Contains a plethora of potent vitamins, minerals, and nutrients. Known for its ability to help skin retain a lot of moisture (an alternative to hyaluronic acid). Osea Malibu uses three types of algae in this formula: Gigartina skottsbergii, undaria pinnatifida, and macrocystis pyrifera.
  • Hyaluronic Acid: Naturally produced by our body, hyaluronic acid exists deep within the layers of the skin and works to support the skin’s internal structure and function. Hyaluronic acid is a humectant commonly touted for its ability to retain up to 1000x its molecular weight in moisture. Contrary to popular belief, hyaluronic acid is not a moisturizer on its own. The molecule, instead, draws moisture from its surrounding environment.
  • Sodium Hyaluronate: A water soluble salt of hyaluronic acid with a lower molecular weight than hyaluronic acid. The lower molecular weight allows the sodium hyaluronate molecular to penetrate the skin at a deeper level than hyaluronic acid (which has a larger molecular weight).

Preservatives Used:

  • Potassium Sorbate: Natural | EWG Score: 2
  • Citric Acid: Natural | EWG Score: 1-2

Concerning Ingredients
  • Potassium Sorbate: Potassium sorbate is the potassium salt of sorbic acid and can be derived from natural sources such as fruits. It is used primarily as a preservative instead of parabens because of its strong antimicrobial anti-fungal properties. Potassium sorbate has caused some controversy because of evidence that it can cause irritation due to allergic reactions in rare cases. There is scant evidence, however, that the low concentrations used in skin care (below .5%) create a high risk for skin irritation. (source | source)
All Ingredients

Ingredients as of: 03/09/2020

aqua, gigartina skottsbergii extract*, macrocystis pyrifera extract*, undaria pinnatifida extract*, sodium hyaluronate Natural | Humectant | EWG Score: 1 , hyaluronic acid Natural | Humectant | EWG Score: 1 , potassium sorbate Natural | Preservative | EWG Score: 2 , citric acid Natural | Preservative | EWG Score 1-2 , lonicera caprifolium extract, lonicera japonica extract, chlorophyll Natural | Anti-Bacterial | Pigment | EWG Score: 1


The Osea Malibu Hyaluronic Sea Serum claims to be a lightweight serum that adds a burst of hydration to your skin care routine. We put this fan favorite to the test and added the Hyaluronic Sea Serum to a variety of daily routines for two weeks. We tested the serum with various other serums, moisturizers, and experimented with wearing it by itself after cleansing. At the end of the trial, this organic moisturizer earned a Product Design & Effectiveness Score of an “A+” for it’s lightweight, fast absorbing, non-sticky formula. Here’s the deal with this serum: it cannot be worn by itself. Hyaluronic acid works as a humectant which draws moisture from the environment towards and into the skin. If no additional moisturizing product is layered over the Hyaluronic Sea Serum, there is very little moisture in the environment for the hyaluronic acid to draw from. This can cause the skin to feel dry, tight, and dehydrated. Through our trial, we discovered that the best way to wear this serum is alongside a water-based moisturizer or serum. When applied after cleansing or toning, this serum has a very lightweight gel texture that absorbs quickly into the skin. There is a slightly tacky feeling left over for a few seconds as the serum seeps into the skin. Once absorbed, it was easy to layer on another serum, facial oil, or moisturizer without feeling weighed down by all of the layers. The Hyaluronic Sea Serum has practically no scent and a little of this serum goes a very long way. The texture is so easy to spread around the skin that we were able to get away with using one very small drop per use.

Product Effectiveness Summary

Works Best For: All Skin Types

Official Usage Instructions: After cleansing, apply this plumping serum onto skin to deliver an instant antioxidant boost. Allow to absorb. Seal in with OSEA moisturizer of choice. Use morning + night.

Ease of Use: Easy to incorporate into an existing routine as a serum. Not moisturizing on it’s own. Must be paired with a moisturizer (preferably water-based) to experience the full benefit. 

Most Notable Results

  • Must be paired with a moisturizer for maximum benefit
  • Lightweight gel formula
  • Absorbs quickly with a matte finish
  • Non-greasy formula (won’t clog pores)
  • little goes a very long way
  • Slightly tacky finish that fades when fully absorbed
  • Unscented

Claims Not Met

  • None: This product does not make claims of effectiveness that we did not experience.


We’ve analyzed 305 customer reviews for the Osea Malibu Hyaluronic Sea Serum from 7 different online retailers (including stores like Detox Market, Follain, Credo, and Petit Vour). Across all retailers, the Hyaluronic Sea Serum earned an average customer review of 4.6/5 stars–earning a grade of “A-” for our Online Customer Review Score. After analyzing the reviews, it was obvious that the main complaint about this serum is that it doesn’t behave like a true moisturizer (i.e. it can’t be worn solo as a moisturizing serum, it must be paired with other serums or moisturizers). Customers who wore this serum on its own mentioned experiencing “dry,” “tight,” and “dehydrated” skin. Customers who used the Hyaluronic Sea Serum with other skin care products were more likely to leave positive reviews. On the positive side, positive reviews raved about this serums ability to create a dewy, hydrated, glowing appearance with both day and night use. Other positive comments include the serums easy-to-apply texture, fast absorbing formula, and ability to work for sensitive and acne-prone skin. See Pros & Cons below for a full summary.

Customer Review Summary

Reviews last evaluated: 03/12/2020

  • *Osea Malibu: 165 Reviews | Average Score: 4.6 Stars
  • *Detox Market: 32 Reviews | Average Score: 4.8 Stars
  • *Follain: 24 Reviews | Average Score: 4.0 Stars
  • *Credo: 44 Reviews | Average Score: 4.6 Stars
  • *Aillea: 18 Reviews | Average Score: 4.9 Stars
  • *Petit Vour: 13 Reviews | Average Score: 4.6 Stars
  • Bloomingdale’s: 9 Reviews | Average Score: 4.3 Stars


  • Lightweight gel formula
  • Absorbs quickly
  • Helps to increase moisture retention from other skin care products
  • Has a matte finish
  • Non-greasy formula
  • Works well with acne-prone & sensitive skin
  • Layers well with other serums & moisturizers
  • A little goes a very long way
  • Unscented


  • Must be paired with a moisturizer for maximum benefit
  • Can make skin feel “dry” when used alone
  • Slightly tacky finish that fades when fully absorbed

This Product Was Made By...

OSEA Malibu

website: www.oseamalibu.com | year founded: 1996

OSEA Malibu is an organic skin care brand that has been committed to non-toxic skin care for over 20 years. OSEA was the first company to sign the Environmental Working Group’s “Compact for Safe Cosmetics” pledge and has lead the charge ever since. The line is totally plant-based, vegan, and free of synthetic ingredients. Responsibly sourced organic seaweeds are the star ingredients in nearly all of OSEA’s products. Top products include the Ocean Cleanser, Vitamin Sea Serum, and Hyaluronic Sea Serum.


This Article Was Written By...

Diane Elizabeth K., Founder at SkinCareOx.com

Diane Elizabeth founded Skin Care Ox in 2016 after her personal struggle to find truly clean, natural, and organic products. Leveraging her background in biomedical engineering, scientific research + analytics, and entrepreneurship, she created Skin Care Ox to be an easy-to-use resource to find real clean beauty options. Since then, her articles have been read by over 3 Million people and have helped millions choose cleaner alternatives. She currently lives in Colorado with her husband and growing family.
Review Standards & Process

Skin Care Ox product reviews are 100% brand neutral. Skin Care Ox does not accept compensation in exchange for reviews. Additionally, there are no paid advertisements on Skin Care Ox. From time to time, brands will submit products to our team for review. Whether we procure the products ourselves or they are submitted to our team for review---our reviews remain honest and neutral.

Skin Care Ox is primarily funded through affiliate commissions. Meaning, when you purchase a product via a link from our website, we earn a small commission on the sale from the retailer (at no additional cost to you). Skin Care Ox is a member of numerous affiliate networks representing hundreds of cleans beauty brands and retailers. Because of this, no single brand or company has control over our review decisions.

Finally, every product we review undergoes our Research and Review Process. This includes faithfully trialing the products for a minimum of two weeks, rigorously researching each ingredient, and consolidating real user reviews from across the web.



The product contains only natural ingredients (non-synthetic or lab created). It does not contain anything artificial or synthetic.



The product has been formulated with 100% organically sourced and/or certified organic ingredients.



This product does not contain ingredients which have been genetically modified.



All of the ingredients contained in the product are free from gluten, wheat, and ingredients which are commonly contaminated with gluten.



The product is made without animal products or byproducts such as beeswax, honey, milk, eggs, etc.



The product has received an official organic certification from a third party organization such as the United States Department of Agriculture (USDA Certified Organic), ECOCERT, Australian Certified Organic, and others.


*OSEA Malibu – Blemish Balm Organic Moisturizer ($48)

Acne skin types--say hello to your new favorite moisturizer! We gave this organic moisturizer for acne to five testers with various kinds of acne and blemish prone skin types and they all rated it 10/10. It's ultra-lightweight, making it great for oily skin types, but it is also packed with hydrating organic algae for drier skin. It is also made with a great blend of acne-fighting ingredients like tea tree oil, rosemary, thyme, and juniper essential oil. Truly a must-try for acne skin types!



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