Review / First Impressions: Hylamide C25 Booster (Vitamin C Derivative Serum)

Where to purchase: From the Deciem Website HERE

Price: £25

Volume: 30ml

What is it?: A Vitamin C Derivative (Not pure L-AA) Serum to help brighten the skin. Should be non-irritating.

Brand Description: 25% Ethylated Vitamin C booster helps improve the skin tone.


Which Skin Type?: Dry Skins (unless you like facial oils too) and also those who can’t handle pure L-AA or low pH products.


Vegan?: Yes

Cruelty Free?: Yes

Packaging: Glass Dropper Bottle

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Directions: ”Apply twice daily as adjunct skincare to offer radiance and visible evenness. Can be used as part of any skincare regimen before the application of moisturizers and/or makeup.” (From the Deciem Website)

How I use it: I applied this in the serum step (just after toning). It was difficult to put anything else on top other than cream. I couldn’t use this in the AM as it didn’t layer well with my Missha Aqua Sun Gel (review HERE).

I WILL SAY – I told my friend about the unpleasant oily texture and she said that what she does when using hers, is that she applied very little – so that she can spread the oil very far, and it makes it more manageable on the skin.

Key Ingredients: Ethylated Ascorbic Acid – a form of Vitamin C (a derivative – that is stable, so you don’t need to put it in the fridge or keep air away. A decent skin brightener. Deciem state that EAC is supposed to be anti-inflammatory as well and collagen production boosting too.

Apparently 0.5% of phenylethyl resorcinol is more effective than 1% of kojic acid (but note – that is what the manufacturer says and it’s not from an independent source).

Full Ingredients: Propanediol, Ethyl Ascorbic Acid 25.0%, Hydroxyphenoxy Propionic Acid, Phenylethyl Resorcinol.

A short and sweet ingredients list!

NOTE: The Incidecoder have a full ingredient breakdown HERE

(Also apparently it is Propanediol that is the thing that provides this oily texture)

Texture: Oily. This feels like a facial oil. It doesn’t disappear, it’s also mildly sticky. If you like thicker facial oils, I think you would enjoy this, but for me – I’m not a fan of facial oils full stop. So it wasn’t pleasant using this or spreading this around the face. And I found it difficult to layer products on top.


Fragrance?: No added fragrance / Essential Oils

Good Under Makeup?: No because of the oil slick – it wouldn’t work well under my foundation

How long have I been using this?: I tried this 3 times before giving up (I couldn’t handle the texture as I’m not a fan of oily products).

The Effect?: I won’t deny that this does moisturise the skin. I didn’t use this long enough to see any brightening effects (but that’s because I just couldn’t stand the texture.

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2.00 £

What I like:

  • No added fragrance
  • Non-irritating

What I don’t like:

  • Oily texture (doesn’t disappear or fully absorb) – for me, it feels like my skin can’t breathe.
  • Due to this texture, I found it difficult to use this in the AM (didn’t play nicely with my SPF – so could only try at night).
  • I couldn’t finish using this – the texture was too greasy for me (not lightweight like the Huda Wishful Facial Oil – Review HERE)

Overall Rating and Conclusion: 2/5 – I’m not going to comment on the effectiveness of this too much, because I didn’t use this long enough to see results BUT I do usually think that L-AA (i.e. pure L-Ascorbic Acid) is more effective at brightening and being an antioxidant, compared to derivatives. I will say, as this is a derivative serum, it’s not in a more acidic base, so this product didn’t irritate or mildly sting, which was nice. I’m personally not a fan of facial oils, so a product like this, which is oily in nature, is not going to go well with me – so that is why I’m giving a low score.

I do think dry skins could really enjoy this OR if you want to use this, I would suggest putting only a little bit, to thin out that oily texture.

Would I repurchase?: No. I don’t like the oil texture.

Dupe?: I don’t have a specific dupe for this in terms of the exact Vitamin C derivative used BUT – please check out my Vitamin C Review Section to check out what Vitamin C or Vitamin C Derivative products I have tried and tested HERE – I much prefer water-based Vitamin C products (but I do understand that those oxidise much quicker).

My Skin Type: I am acne prone and have slightly dehydrated combo skin. My skin is usually tight where the cheeks and eye area is and the outer parts of my face. My T zone is oily. My skin isn’t a fan of thick/heavy formulas so I opt for lightweight formulas to prevent it from clogging up. My skin doesn’t like essential oils either and I try to avoid fragrance when I can.

Disclaimer: I am a skincare enthusiast and not a skin expert. I am not qualified to give out dermatological advice. This type of advice should only be given by a medical practitioner. Upon trying / using any of the reviewed products on the blog, please follow the manufacturer’s instructions and warnings and please seek medical advice if needed.


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