Sí Serum Antioxidante Vitamina C

Name: Sí Serum Antioxidante Vitamina C
Brand: ESTELÍ
SKU: FC-SI-30
Rating: 5.0 (8 reviews)

Vitamin C Antioxidant Serum

$194.00

1 fl oz / 30 ml

Naturally Aromatic · Small-Batch · Leaping Bunny Certified

A silky vitamin C serum formulated for brighter, more even-looking skin. Made with 10% tetrahexyldecyl ascorbate, an oil-soluble vitamin C derivative, in a nourishing base of sugarcane-derived squalane, rosehip CO₂, and golden jojoba. For skin that looks dull or uneven, with a soft, supple finish and delicate rose-geranium aroma.

DETAILS

What It Is What It Is

Sí is an oil-based vitamin C serum made with 10% tetrahexyldecyl ascorbate (THD), an oil-soluble form of vitamin C, to support a brighter-looking, more even-looking complexion.

Sugarcane-derived squalane, organic rosehip CO₂, and organic golden jojoba create a silky, nourishing base that softens skin and helps retain moisture. Organic rose and geranium lend a delicate floral aroma.

A daily serum for skin that looks dull, feels dry, or needs replenishment.

Benefits Benefits

Brighter-looking skin: 10% THD vitamin C helps improve the appearance of dullness and uneven tone.
Softness and suppleness: Squalane and organic jojoba condition skin, leaving it feeling smooth and nourished.
Moisture retention: Botanical oils help keep moisture in, easing the feel of dry skin.
A luminous finish: Organic rosehip CO₂ and a silky oil base leave skin looking fresh and radiant.

Key Ingredients Key Ingredients

10% THD Vitamin C · Tetrahexyldecyl Ascorbate
An oil-soluble vitamin C derivative that helps improve the appearance of dullness and uneven tone. Blends into the nourishing oil base for daily radiance care.

Sugarcane-Derived Squalane
A lightweight emollient that softens skin and helps retain moisture. Gives Sí its silky glide and smooth finish.

Organic Rosehip CO₂ Extract
Rich in naturally occurring fatty acids, this botanical extract helps condition dry skin and contributes to the serum’s golden color.

Organic Golden Jojoba Oil
A liquid botanical wax that softens and conditions skin, helping it feel supple and comfortable.

Organic Rose + Geranium
Aromatic flower oils that lend a delicate floral scent, bringing a soft botanical character to the daily ritual.

The Ritual The Ritual

Use morning or evening after cleansing and misting with Rosa Jamaica.

Warm 2–3 drops between fingertips and gently press into slightly damp skin on the face and neck.

For additional nourishment, follow with Oro Rosa Face Oil as needed. If using a moisturizer, apply it before Sí. In the morning, finish with sunscreen.

Use consistently as part of your daily ritual.

Care & Storage

Store away from direct heat and sunlight, with the bottle tightly closed. Natural botanical ingredients may cause slight variations in color and aroma between batches.

For external use only. Avoid contact with eyes. Discontinue use if irritation occurs.

Scent Profile Scent Profile

Light, softly floral, and green.

Organic rose and geranium lend a delicate floral aroma, softened by the subtle earthy character of rosehip CO₂ and golden jojoba. The scent stays close to the skin.

Made without synthetic fragrance. Natural botanical ingredients may create slight variations in aroma from batch to batch.

Full Ingredients Full Ingredients

INGREDIENTS / INCI

Squalane, Rosa Canina Fruit Extract*, Simmondsia Chinensis Seed Oil*, Tetrahexyldecyl Ascorbate, Tocopherol, Beta-Sitosterol, Squalene, Rosa Damascena Flower Oil*, Pelargonium Graveolens Flower Oil*, Rosmarinus Officinalis Leaf Extract*

*Certified organic ingredient.

SELECTED ORGANIC BOTANICALS

Made with certified organic rosehip CO₂ extract, golden jojoba oil, rose flower oil, geranium flower oil, and rosemary leaf extract.

Tetrahexyldecyl ascorbate (THD) is an oil-soluble form of vitamin C included at 10% to support brighter-looking, more even-looking skin.

Sugarcane-derived squalane gives the formula its silky, lightweight glide, while botanical oils and vitamin E soften and condition skin. Rose and geranium provide its delicate natural aroma.

Vitamin C, the ESTELÍ Way

At markets, customers often asked me: Do you make a vitamin C?

I wanted to say yes—but first, I wanted to make a serum I would reach for myself. Something that brought vitamin C into the botanical oils I already loved working with, with a texture and scent that made daily use a pleasure.

I chose tetrahexyldecyl ascorbate, an oil-soluble form of vitamin C, and paired it with sugarcane-derived squalane, organic rosehip CO₂, and golden jojoba. Rose and geranium gave it a delicate floral finish.

Sí became my answer: a silky, golden serum for brighter-looking skin, made with the nourishment and sensory care at the heart of ESTELÍ.

Artwork by Eva Magill-Oliver

Inside the Formula

Golden oil dropper for SÍ Vitamin C Serum with oil-soluble vitamin C

10% THD Vitamin C

Tetrahexyldecyl ascorbate is an oil-soluble form of vitamin C chosen to support brighter-looking, more even-looking skin. At 10%, it brings targeted radiance care to a silky, nourishing serum.

Sugarcane-Derived Squalane

A lightweight emollient that helps retain moisture and soften dry skin without a heavy feel. Its silky texture gives Sí a smooth glide, leaving skin feeling supple and comfortable.

Rosehip CO₂ extract, a key botanical ingredient in Oro Rosa Supercriticals Face Oil

Organic Rosehip CO₂ Extract

A concentrated botanical extract rich in naturally occurring fatty acids and antioxidants. Chosen to nourish and condition skin that feels dry or depleted, it leaves skin feeling softer and more supple.

Rose hydrosol ingredient for Rosa Jamaica Hydrating Face Mist

Organic Rose Flower Oil

Chosen for its delicate floral aroma, organic rose brings warmth and softness to the formula’s scent. Paired with geranium, it creates a subtle botanical fragrance that stays close to the skin.

BEST FOR

Skin that looks dull or uneven, feels dry, or needs replenishment. Especially suited to those who enjoy the nourishing feel of a face oil and want vitamin C as part of a simple daily routine.

GOOD TO KNOW

Made with 10% tetrahexyldecyl ascorbate (THD), an oil-soluble vitamin C derivative, in a nourishing blend of squalane and botanical oils.

Naturally scented with organic rose and geranium flower oils. Made without synthetic fragrance; patch test before first use.

THE FORMULA

Every Ingredient, Explained

A closer look at the ingredients in Si, why we've selected them, and the role each plays in the formula.

Our Ingredient Standards

Considered Sourcing

Sí brings together sugarcane-derived squalane, organic golden jojoba, and concentrated organic rosehip CO₂ extract, selected for their composition, quality, and contribution to the skin. Organic rose and geranium flower oils add a delicate botanical aroma, while oil-soluble THD vitamin C provides focused care for brighter-looking skin.ity.

Purposeful Formulation

Every ingredient serves a purpose. THD vitamin C supports brighter-looking, more even-looking skin, while squalane, rosehip CO₂, and jojoba soften, condition, and help retain moisture. Vitamin E and the rosemary antioxidant present in the rosehip extract help protect the oils from oxidation. Together, they create a nourishing serum with a silky finish

Full Transparency

We share the complete ingredient list and explain each ingredient’s role, including the antioxidants that help maintain the oils’ freshness. Certified organic ingredients are clearly marked, and the vitamin C form and its 10% concentration are disclosed. Sí is naturally aromatic, with rose and geranium providing its soft floral character, without synthetic fragrance.

QUESTIONS

What kind of vitamin C does Sí contain? What kind of vitamin C does Sí contain?

Sí contains 10% tetrahexyldecyl ascorbate (THD), an oil-soluble vitamin C derivative. It blends into the squalane and botanical oils to support brighter-looking, more even-looking skin.

Does a higher vitamin C percentage mean a better serum? Does a higher vitamin C percentage mean a better serum?

Percentage is only part of the picture. The form of vitamin C and the complete formula also matter, so different vitamin C serums cannot be compared by concentration alone. Sí pairs 10% THD with squalane, organic rosehip CO₂, and jojoba for radiance care with the nourishment of a face oil.

Why is Sí oil-based? Why is Sí oil-based?

Its oil-soluble vitamin C blends with squalane and botanical oils to create a silky, conditioning serum. This makes Sí especially appealing to those who want vitamin C alongside care for skin that feels dry or needs replenishment.

Should I use it morning or night? Should I use it morning or night?

Either fits. Apply 2–3 drops after cleansing and misting, then gently press into the face and neck. If using a moisturizer, apply it before Sí. In the morning, finish with sunscreen.

How does Sí fit with Rosa Jamaica and Oro Rosa? How does Sí fit with Rosa Jamaica and Oro Rosa?

Mist with Rosa Jamaica first, then press Sí into slightly damp skin. For extra nourishment, follow with a small amount of Oro Rosa. You can also use Sí in the morning and Oro Rosa in the evening.

Is Sí suitable for sensitive skin? Is Sí suitable for sensitive skin?

Sí was formulated to feel nourishing and comfortable, but every person’s skin is different. It contains organic rose and geranium essential oils, which may not suit skin sensitive to aromatic botanicals. Patch test before first use and discontinue if irritation occurs.

How long does it take to notice results? How long does it take to notice results?

Skin may feel softer and more supple after application, while improvements in the appearance of dullness and uneven tone develop gradually with consistent use. Results vary from person to person.