TL;DR
What BLH308™ is, how it works, and why the science behind this botanical complex matters for long-term hair health.
Hair care is full of proprietary ingredient names. Most of them are marketing. A few of them are something more.
BLH308™ is one of the rare cases where the science holds up.
It’s the active botanical complex in Bomme’s Root Renewal Supplements — the ingredient behind our hair supplements and the one we talk about most, for a reason that has nothing to do with branding.
It has published clinical data behind it.
This post is our attempt to explain what BLH308™ actually is, what the research shows, and why it matters for anyone thinking seriously about long-term hair health.
In short, BLH308™ is:
- a botanical complex combining persimmon leaf, green tea, and sophora fruit
- designed to support the internal environment that influences hair follicles
- supported by a 24-week randomized clinical study showing improvements in hair density and thickness
These three points are why BLH308™ plays a central role in the Bomme system.
What BLH308™ Is
BLH308™ is a proprietary botanical complex formulated from three plant-derived ingredients:
- Persimmon leaf extract (Diospyros kaki) — the primary active, with a long history of use in East Asian traditional medicine for its antioxidant and anti-inflammatory properties
- Green tea extract (Camellia sinensis) — particularly rich in EGCG (epigallocatechin-3-gallate), a polyphenol with well-documented antioxidant activity
- Sophora fruit extract (Sophora japonica) — known for its anti-inflammatory and immunomodulatory properties
These three extracts are formulated together in a specific ratio, not as a blend of convenience, but because their mechanisms are complementary. Each addresses a different aspect of the internal environment that influences hair follicle health.
Why Internal Support Matters for Hair
Before getting into the clinical data, it helps to understand why an oral supplement fits into a scalp-first hair care system at all.
Topical care — cleansing, leave-in actives, scalp barrier support — addresses what's happening at the surface. But hair follicles don't exist in isolation. They're influenced by the broader internal environment: oxidative stress levels, inflammatory signaling, nutrient availability, and hormonal balance all play a role in how follicles cycle through their natural growth, rest, and shedding phases.
Certain internal factors — including elevated levels of inflammatory markers and oxidative stress — have been associated with disruption to healthy hair cycling patterns. This is particularly relevant in the context of androgenetic alopecia, where inflammatory activity in the follicular environment is well-documented in the research literature.
Topical care cannot address these systemic inputs. That's the layer BLH308™ was formulated to support.
Why These Botanicals Matter for Hair Biology
Each ingredient in BLH308™ has a specific biological rationale:
Persimmon leaf extract is rich in flavonoids such as quercetin and kaempferol. In preclinical studies, these compounds have demonstrated antioxidant and anti-inflammatory activity in follicle dermal papilla cells — the cells that directly regulate hair follicle activity. It has also been shown to reduce expression of 5α-reductase, an enzyme associated with androgenetic hair thinning.
Green tea extract (EGCG) has separately demonstrated the ability to inhibit 5α-reductase activity and to support hair growth by influencing key signaling pathways (ERK and AKT) in follicle dermal papilla cells in research settings.
Sophora fruit extract contains isoflavone glycosides — including sophoricoside — that help inhibit IL-6 and COX-2 activity. This matters because elevated IL-6 levels have been found in the balding zones of androgenetic alopecia, suggesting an active inflammatory environment in areas of thinning.
Together, these three botanicals work across overlapping anti-inflammatory and antioxidant pathways — supporting the internal scalp environment in ways that may complement what's happening with topical care.
The Clinical Study
BLH308™ was evaluated in a published, randomized, double-blind, placebo-controlled clinical trial conducted at the Global Medical Research Center in Seoul, Korea, in collaboration with the Department of Dermatology at Yonsei University College of Medicine — one of Korea's leading academic medical institutions.
The study enrolled 88 healthy adults between the ages of 19 and 60, with participants randomized equally into a test group (oral BLH308™ twice daily) and a placebo group. The study ran for 24 weeks, with assessments at baseline, week 8, week 16, and week 24. Hair density, thickness, and gloss were measured using objective clinical tools.
What the study found:
At 24 weeks, participants in the BLH308™ group showed statistically significant improvements in both hair density and hair thickness compared to the placebo group:
- Hair density increased in the test group and decreased in the placebo group over the course of the study, with a statistically significant difference between the groups at week 24 (p = 0.0015)
- Hair thickness (diameter) similarly increased in the test group while decreasing in the placebo group, with a highly significant difference at week 24 (p = 0.0001)
- Improvements in hair density were measurable as early as week 8, suggesting a relatively early response to oral supplementation
- Hair gloss showed directional improvement in the test group, though this did not reach statistical significance between groups
No serious adverse events were recorded, and adverse event rates were comparable between the BLH308™ group and the placebo group.
The full study is published in Skin Research and Technology (Ham et al., 2023) and is available here: https://doi.org/10.1111/srt.13448
Individual results may vary. This product is not intended to diagnose, treat, cure, or prevent any disease.
What the C&T Allē Recognition Means
Earlier this year, BLH308™ was named a finalist in the 2026 Cosmetics & Toiletries Allē Awards in the Cosmetic Active — Hair/Scalp category. Bomme also received finalist recognition in two additional categories: Finished Indie Formula — Hair Care/Scalp (for the Toner and Shampoo) and Finished Indie Formula — Nutricosmetics (for the Supplements).
The Allē Awards are a peer-reviewed industry recognition that evaluates the science behind cosmetic actives — not packaging, branding, or market performance. Finalist recognition in the Cosmetic Active category specifically reflects the quality of the ingredient science: the biological rationale, the formulation intent, and the clinical evidence behind the active itself.
For a small indie brand, recognition like this is meaningful not because of the award itself — but because of what it signals. Ingredient-level scrutiny is different from consumer-facing marketing. It's the kind of evaluation that asks: does the science hold up?
In this case, we believe it does.
How BLH308™ Fits the Bomme System
BLH308™ is Step 3 in the Bomme Ritual — but that framing undersells its role.
The three-step system is designed so that each layer supports a different biological need:
- Step 1 (Shampoo) prepares the scalp — removing buildup, supporting barrier function, creating a clean foundation for what comes next
- Step 2 (Toner) delivers targeted leave-in actives consistently at the scalp level, where follicle signaling is most directly influenced
- Step 3 (Supplements / BLH308™) addresses the internal environment — the oxidative and inflammatory inputs that topical products cannot reach
Remove any one layer, and the system becomes less complete. The supplements don't replace topical care. Topical care doesn't replace internal support. The combination is the point.
Hair biology responds to patterns — to consistent, coordinated inputs maintained over time. That's what a system is designed to provide.
A Note on Timelines
The clinical study ran for 24 weeks. Statistically significant results in hair density appeared at week 8 and continued through week 24, with the largest improvements at the end of the study period.
This aligns with what we know about hair biology: follicles move through the hair growth cycle — the phases of growth (anagen), transition (catagen), and rest (telogen) — on timelines measured in months, not days. Progress often becomes measurable before it becomes visible. The first 90 days of a routine are about regulation and stabilization — not transformation.
Consistency over time is what allows the biology to respond.
If You're New Here
Bomme is scalp-first hair care designed for people who want long-term hair health — without urgency, hype, or quick fixes.
If you're exploring a scalp-first routine, the Bomme Ritual was designed around this inside + outside philosophy.
BLH308™ is one reason we're confident in that approach. Not because it's a miracle ingredient — but because it's a studied one, with a mechanism that makes biological sense and clinical evidence to support it.
The goal isn’t to override biology.
It’s to support the conditions that allow it to work as intended.
Hair health is biological. Innovation should be, too.
