There's a reason certain formulations become non-negotiable in a skincare ritual. #1 The Strengthening Serum is one of them. A foundational first step in your morning routine, this supercharged niacinamide serum targets a range of common skin concerns, whilst cultivating stronger, hydrated, healthy-looking skin.
Why It’s Different
Not all skin concerns begin at the surface. Dehydration, redness, uneven tone and sensitivity are often symptoms, not causes. The origin lies deeper, within the skin’s own defence system: its immunity. When skin immunity is compromised, it becomes reactive, imbalanced, and visibly diminished. When functioning optimally, skin is self-regulating and maintains hydration, resilience and luminosity.
#1 The Strengthening Serum works to strengthen skin barrier function by harnessing a Vitamin B Complex, including niacinamide, which has been refined over decades of clinical research and innovation. “#1 The Strengthening Serum is the ideal starting point with RATIONALE, as it builds a strong structural foundation and enhances skin resilience, something required for all skin types and concerns,” says Rhylee Kopania, Regional Educator at RATIONALE.
The Actives
This serum harnesses four primary active ingredients that work in synergy. Niacinamide strengthens the skin barrier, smooths texture and helps to even tone over time, while also regulating oil production and reducing redness. Hyaluronic acid draws moisture into the skin, resulting in a visibly plumper appearance, while peptides reinforce the skin’s architecture to support firmness and lasting hydration. Antioxidants complete the formula, helping to neutralise free radical damage that accumulates from daily environmental exposure. Together, these actives work in synergy to support skin health, reinforcing why this truly is the winning formula.
"If the skin is showing signs that it isn't functioning optimally—including feelings of dehydration, a lacklustre appearance, redness, or potential breakouts—this can indicate a need to introduce #1 The Strengthening Serum,” advises Rhylee.
Targets + Results
Because the formula supports skin barrier function rather than targeting a single concern, its benefits are broad.
In a 56-day clinical trial with 22 participants:
91%
experienced improved skin hydration.
82%
experienced a boost in radiance.
82%
experienced enhanced skin nourishment
Where It Fits in Your Skincare Ritual
#1 The Strengthening Serum is the first step of your morning ritual—applied first, before anything else. The sequencing is deliberate. By supporting the skin's barrier function from the outset, it enhances the efficacy of every product that follows. "It builds a strong structural foundation and enhances skin resilience—something required for all skin types and concerns," adds Rhylee. For new RATIONALE clients, it's almost always where the conversation starts.
#1 The Strengthening Collection, Explained
Each Essential Six Collection focuses on one key benefit—such as strengthening, brightening or nourishing—while delivering the same essential nutrients via a range of delivery systems, such as serums, hydragel and crèmes, to suit each skin type.
- #1 The Strengthening Serum: Ideal for combination skin.
- #1 The Strengthening Crème: deal for dry or mature skin.
- #1 The Strengthening Hydragel: Ideal for dehydrated skin.
- #1 The Strengthening Mask: This once-weekly treatment is suitable for resilient skin, to supercharge your ritual and results.