Firm + Replenish

A must after cleansing, this serum restores your skin barrier by replenishing your natural moisturizing factor (NMF) and the essential lipids in the skin. Featuring a double dose of our patented B-SILKTM PROTEIN, a multi-tasking polypeptide that combines the power of collagen and elastin into one, it keeps your skin supple with nourishing ceramides and squalane plus elasticity building, skin firming amino acids for better skin health.

Formulated without: Fragrance, Silicones, Parabens, Mineral Oil, Petrolatum

We are: EWG Verified, Leaping Bunny Certified, Vegan

Do you cleanse daily?* You need this. Apply two to three pumps to face, neck, and décolletage after cleansing and/or exfoliating in the AM and PM. For best results, follow with your favorite Eighteen B Moisturizer.

Pro Tip: If you’re using any active treatments (retinol, vitamin c etc.) or oils, apply them before Firm + Replenish Serum so B-SILKTM PROTEIN can lock in the benefits. *If you’re not cleansing daily, we should talk. It's important to start and end the day with fresh, clean skin. Your pores will thank you (and be smaller)!

[ "Water (Aqua), Squalane, Pentylene Glycol, sr-Wasp Spider Polypeptide-1 Oligopeptide-178 (Silk Protein), Sodium Hyaluronate Crosspolymer (Hyaluronic Acid), Ceramide AP, Ceramide EOP, Ceramide NP, Alanine, Arginine, Aspartic Acid, Glycine, Histidine, Isoleucine, Phenylalanine, Proline, Serine, Threonine, Valine, Cholesterol, PCA, Sodium PCA, Sodium Lactate, Phytosphingosine, Sodium Lauroyl Lactylate, Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, Xanthan Gum, Carbomer, Polysorbate 60, Hexylene Glycol, Ethylhexylglycerin, Caprylyl Glycol, Sorbitan Isostearate, Disodium EDTA, Phenoxyethanol." ]


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Since we created B-SILK™ PROTEIN, we needed to prove that it is really as great as we think it is. In a clinical trial, based on expert grading evaluations:

After 4 weeks

After 8 weeks


Showed a reduction in the appearance of fine lines



Showed improved elasticity


+80%saw firmer, more nourished skin after 4 weeks of using Firm + Replenish Serum
Serums are treatment products that deliver concentrated doses of “active” ingredients to fix the things you want to fix (though we think you look fab)!

Serum 101:

  • Apply serums first because you want high performance actives close to the skin to work well.
  • Our serum features B-SILK™ PROTEIN to reinforce your skin’s natural barrier and lock in that retinol or vitamin c serum you’re also using. Use them together. Daily.
  • Serums help with hydration; a key feature of ours is replenishing your NMF; but they’re not a replacement for your moisturizer.
  • Can you wear multiple serums at a time? Absolutely! See our note above.

58 reviews

100% of reviewers would recommend this product to a friend.






Effortless and Effective

My skincare regiment is pretty low-maintenance, but this serum has convinced me to add another step to my routine. It glides on smoothly and instantly improves my skin's texture without feeling heavy or oily. I also love that it pairs well with the EighteenB hydrogel moisturizer, which I use daily under my sunscreen and makeup - and everything just glides on effortlessly on top of it. Also, I feel like I am giving my face an added layer of protection against all of the pollutants I encounter living in NYC. I highly recommend trying this product!

This serum really works!

I am 62 and after two weeks of using Eighteen B serum, the skin around my face and neck visibly firmed up. Any woman my age would love this product!

Instantly addicted!

light and refreshing feeling going on and tightens my skin over night. My face has never looked and felt better. I don’t want to use any other ant-aging products again.

A Gamechanger

I have never experienced a serum like this- not only is it a dream to apply, but I see real, visible results. It pairs so well with my retinol and vitamin C serums- as if it locks in the treatment while keeping my skin noticeably hydrated. I feel naked without applying it!

I 100% love this serum...

I love this serum so much I practically bathe in it. It is the perfect texture. Although a lot goes a long wait I find I want it everywhere and thus use probably 4 or 5 pumps...Not sure if that is too much but I don't care because I am getting really amazing feedback about my skin. Not sure if is the serum or the rich cream but I BET it is both of them combined. LOVE YOU GUYS!!!

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