Biotin Serum Showdown: Tested for 8-Week Hair Density Boost In the quest for thicker, fuller hair, the market is flooded with promises-and the science has caught up. Over the past eight weeks, we put several biotin-based serums to the test, measuring their impact on hair density, strength, and overall vitality. From the stalwart 5% Minoxidil Spray to the holistic Nioxin Scalp + Hair Thickening System, each contender brought its own philosophy: medical precision, botanical synergy, or a blend of both. The 5% Minoxidil Spray stood out as the no-nonsense hero, leveraging its well-documented role in stimulating hair growth. Its blend with biotin added a nurturing touch, creating a formula that felt like a double dose of commitment. Meanwhile, the Nioxin System approached the issue with a more curated, layered strategy, combining niacinamide, biotin, and a sculpted regimen to address thinning across different hair types. The Hair Growth Serum with rosemary, batana, and castor oil offered a sensory-rich experience, its earthy scents and traditional ingredients evoking a spa-like ritual for the scalp. But not all paths are the same. The Biotin Hair Thickening Serum with natural botanical oils leaned into reparative care, promising to restore volume and shine while tackling breakage. For those craving a multifunctional approach, the GOLDWORLD Rosemary Oil Serum stood apart with its dual-pack design and inclusion of a scalp massager, blending convenience with a touch of luxury. Ultimately, the 8-week results revealed a spectrum of outcomes: some formulas accelerated growth with visible thickness, others deepened shine and resilience, and a few redefined the art of hair care with their unique textures and scents. Whether you're a skeptic or a believer, this showdown offers a roadmap to finding the right ally for your hair's journey-because density isn't just about volume; it's about vitality, too.