OBAGI NU-CIL® Eyelash & Eyebrow Serums — Full Review & Before/After Results
If you've been searching for a clinically credible, prostaglandin-free solution for thinner lashes or sparse brows, the OBAGI NU-CIL® range is likely already on your radar. In this post, we take a deep dive into both the NU-CIL® Eyelash Enhancing Serum and the NU-CIL® Eyebrow Enhancing Serum — covering the science, the ingredients, real clinical before-and-after results, and exactly who each product is right for.
Both serums are available to purchase directly from our clinic at Skin by Science.
What is OBAGI NU-CIL®?
OBAGI Medical is a brand with over 35 years of dermatologist-led innovation behind it. Best known for its prescription-strength skincare systems — including the iconic Nu-Derm® range — OBAGI has applied the same clinical rigour to its NU-CIL® serum line, targeting two of the most common aesthetic concerns in the eye area: thinning eyelashes and sparse eyebrows.
The NU-CIL® range is built around a proprietary peptide complex — specifically Myristoyl Pentapeptide-17 and Myristoyl Hexapeptide-16 — supported by botanical actives and conditioning agents. Crucially, both serums are entirely prostaglandin-free, making them suitable for long-term use without the systemic risks associated with prescription lash treatments.
Both products are backed by blinded clinical studies conducted by Obagi Cosmeceuticals LLC, with photographic evidence collected at baseline and at 12 or 16 weeks — some of which you'll see below.
OBAGI NU-CIL® Eyelash Enhancing Serum (3ml)
The NU-CIL® Eyelash Enhancing Serum is formulated to visibly increase eyelash length, density, and fullness by working at the follicular level to extend the natural lash growth cycle.
What it targets
- Short, sparse, or thin lashes
- Age-related lash thinning
- Lash loss following hormonal changes, nutritional deficiency, or medical treatment
- Patients seeking a safe long-term alternative to prostaglandin-based prescription serums
Key claims (from clinical study data)
- Visibly longer lashes
- Increased lash density and fullness
- Darker, more defined lash appearance
- Results visible from 4–6 weeks; optimal at 16 weeks
OBAGI NU-CIL® Eyebrow Enhancing Serum (5ml)
The NU-CIL® Eyebrow Enhancing Serum applies the same peptide-driven science to brow restoration — addressing sparse, over-plucked, or age-thinned brows with a formula designed to reactivate dormant follicles and extend the anagen (active growth) phase.
What it targets
- Naturally sparse or thin brows
- Over-plucked, waxed, or threaded brows with reduced regrowth
- Age-related or hormonal brow thinning (including menopause and thyroid-related loss)
- Patients wanting a non-invasive alternative or complement to microblading
Key claims (from clinical study data)
- Visibly fuller, thicker brows
- Improved brow definition and density
- Stronger, less brittle brow hairs
- Results visible from 4–6 weeks; optimal at 12 weeks
Size: 5ml | Application: Precision applicator | Frequency: Once daily (evening) | Prescription required: No
Clinical Before & After Results
The following images are taken directly from OBAGI's blinded clinical studies. Photos have not been retouched. Individual results may vary.
All before-and-after images are from blinded clinical studies conducted by Obagi Cosmeceuticals LLC. Photos have not been retouched. Individual results may vary.
Key Ingredients Explained
Both NU-CIL® serums share a core active complex. Here's what each ingredient does and why it matters:
Myristoyl Pentapeptide-17
A biomimetic signal peptide that upregulates keratin gene expression within the hair follicle. Keratin is the structural protein that makes up both lash and brow hairs — stimulating its production directly supports hair fibre elongation and density. This is the primary growth-driving active in both serums.
Myristoyl Hexapeptide-16
Works synergistically with Pentapeptide-17 to enhance follicular stem cell activity and improve hair anchoring strength — reducing premature shedding and supporting the transition from the resting (telogen) phase back into active growth (anagen).
Biotin (Vitamin B7)
An essential co-factor in keratin synthesis. Biotin deficiency is directly linked to hair thinning, brittleness, and loss — both in lashes and brows. Topical delivery ensures targeted support at the follicular level.
Panthenol (Pro-Vitamin B5)
A deeply penetrating conditioner that improves hair shaft flexibility, reduces breakage, and enhances natural sheen. Particularly important for brow hairs, which are coarser and more prone to mechanical damage from grooming.
Swertia Japonica Extract
A clinically studied botanical active shown to stimulate follicular stem cells and support the transition from telogen back into anagen — effectively helping to "wake up" dormant follicles. Particularly relevant for over-plucked brows and age-related lash thinning.
Hyaluronic Acid
Maintains optimal hydration at the follicular microenvironment. A well-hydrated follicular niche supports healthy hair emergence and reduces stress-related hair loss caused by a dry, compromised skin barrier.
Why Prostaglandin-Free Matters
Many patients arrive having researched — or previously used — prescription lash serums containing prostaglandin analogues such as bimatoprost (the active in Latisse®) or isopropyl cloprostenate. While these can produce dramatic results, they carry well-documented risks:
- Iris pigmentation changes — permanent darkening of eye colour in susceptible individuals
- Periorbital fat atrophy — a sunken, hollowed appearance around the eye socket with prolonged use
- Eyelid skin darkening — periorbital hyperpigmentation
- Increased intraocular pressure — a concern for those with glaucoma risk factors
OBAGI NU-CIL® achieves its results through peptide signalling and follicular nourishment — not prostaglandin pathways. This makes it safe for long-term daily use, suitable without a prescription, and the preferred maintenance choice for many clinicians whose patients cannot tolerate prostaglandin side effects.
For a full comparison of prostaglandin-based treatments versus peptide alternatives, see our dedicated guide: Bimatoprost Alternatives: Safe, Effective Options for Lash & Brow Enhancement.
Who Are These Serums For?
NU-CIL® Eyelash Serum is ideal for:
- Anyone with naturally short, sparse, or thin lashes wanting visible enhancement without extensions
- Those experiencing age-related or hormonal lash thinning
- Patients who have tried prostaglandin serums and experienced side effects
- Contact lens wearers (contact lens-compatible formula)
- Those maintaining results following a course of prescription lash treatment
NU-CIL® Eyebrow Serum is ideal for:
- Anyone with naturally sparse, thin, or asymmetric brows
- Those recovering from years of over-plucking, waxing, or threading
- Patients experiencing brow thinning due to menopause, thyroid dysfunction, or postpartum changes
- Those seeking a non-invasive complement or alternative to microblading or brow lamination
- Anyone wanting to improve natural brow density before a professional brow treatment
Neither serum is recommended during pregnancy or breastfeeding without medical advice, for those with active eye or skin infections in the treatment area, or for those under 18 years of age.
How to Use Both Serums
NU-CIL® Eyelash Serum
- Cleanse the eye area and remove contact lenses and makeup
- Apply a single thin line along the upper lash line using the precision brush — as close to the lash root as possible
- Allow to absorb fully before reinserting lenses or applying other products
- Use once daily, preferably in the evening
- Do not apply to the lower lash line or directly into the eye
NU-CIL® Eyebrow Serum
- Cleanse the brow area and remove any makeup or topical products
- Apply a thin layer along and within the full brow line, covering sparse areas from inner to outer corner
- Allow to absorb before applying brow makeup or moisturiser
- Use once daily, preferably in the evening after cleansing
- Do not apply to irritated or broken skin
Both serums require a minimum of 12–16 weeks of consistent use for optimal results. Discontinuing use will gradually return lashes and brows to their pre-treatment state as the natural growth cycle reasserts itself.
Our Verdict
The OBAGI NU-CIL® range represents the most clinically credible, prostaglandin-free approach to lash and brow enhancement currently available without a prescription. The before-and-after data speaks for itself — and the ingredient science behind the results is robust, peer-reviewed, and transparent.
For patients who want real, measurable results without the risks of prostaglandin-based treatments, or who are looking for a safe long-term maintenance option, both NU-CIL® serums are among the strongest recommendations we make at Skin by Science.
Both products are available now from our clinic:
