For centuries, the spiny shrub known to Thais as “som poi” has quietly played a role in kitchens, bathing rooms, and healing traditions across the country. From using its pods as a cleansing shampoo to brewing its leaves for herbal teas, Acacia concinna—once a staple in village life—is now at the center of a scientific renaissance, as researchers unravel its ancient secrets and unlock new health possibilities for the modern age (prosea.prota4u.org; phar.ubu.ac.th).
Som poi is far more than a plant. In many Thai households, especially in rural communities, the dried pods are steeped in scented water for ceremonial ablutions, particularly during Songkran and local New Year’s celebrations, symbolizing purification and new beginnings (prosea.prota4u.org). Its presence is a reminder of a time when nature supplied not only nourishment and beauty, but medicine, household products, and even spiritual protection.
As environmental changes and modern lifestyles create new health challenges, Thais are increasingly looking back to traditional remedies like som poi. Now, a growing body of research is beginning to validate what generations of healers have long believed: Acacia concinna possesses real pharmacological potential, containing a treasure trove of bioactive compounds that may offer benefits in areas ranging from skin and hair care to diabetes, cholesterol management, and infection prevention.
In Thai tradition, som poi has widespread applications. Its leaves and young pods are infused in decoctions to ease body pain, headaches, and mild fevers; they are also regarded as gentle digestive aids and diuretics (prosea.prota4u.org; disthai.com). The pods themselves are perhaps best known as a natural shampoo, thanks to their saponin content, which produces a soapy lather that both cleanses and conditions hair. Grandchildren may recall their elders mixing ground pod powder with water and rinsing away the heat of a Thai summer, leaving hair soft and the scalp refreshed—a practice shared across South and Southeast Asia (prosea.prota4u.org; wikipedia.org).
Som poi is also found gracing Thai food tables—the tangy young leaves add zest to local chutneys, and in some regions, parts of the plant are eaten as a sour vegetable. Such culinary uses overlap with health, since som poi is traditionally believed to cool the body and support digestion.
Yet the most intriguing chapter in som poi’s story is unfolding in laboratories. Recent Thai and international studies have identified Acacia concinna as a rich source of secondary metabolites, particularly saponins, tannins, flavonoids, and phenolic compounds (pmc.ncbi.nlm.nih.gov; pmc.ncbi.nlm.nih.gov). These natural substances help explain the plant’s observed effects—modern science shows that saponins in som poi pods are responsible for their cleansing foaming action, but also have antioxidant and even potential anti-obesogenic properties (pubmed.ncbi.nlm.nih.gov).
A 2023 study published in the journal Plants specifically analyzed som poi collected in northern Thailand, measuring its antioxidant capacity using ethanol, methanol, and water extracts (pmc.ncbi.nlm.nih.gov). The findings showed that som poi extracts contain significant levels of total phenolics and flavonoids, which are widely known for their antioxidant roles—protecting cells from damage caused by free radicals, a process linked to aging and chronic diseases. The study noted an IC50 value (a measure of antioxidant potency) of 25.25 mg/mL for methanol extracts and 41.32 mg/mL for ethanolic extracts, suggesting moderate free radical scavenging activity. Significantly, the highest flavonoid content appeared in water extracts (14.15 µg RE/g), highlighting potential benefits from simple traditional preparations.
Other research has demonstrated further pharmacological promise. Laboratory investigations have shown that Acacia concinna extracts can:
- Inhibit the growth of harmful bacteria such as E. coli and S. aureus, supporting their traditional use for skin conditions and infections (pmc.ncbi.nlm.nih.gov).
- Show anti-lipase, anti-amylase, and anti-glucosidase activities, hinting at potential roles in managing obesity and type 2 diabetes (pmc.ncbi.nlm.nih.gov; pubmed.ncbi.nlm.nih.gov).
- Exhibit cytotoxic effects against certain cancer cell lines in preliminary studies, raising hope for future applications in oncology (pmc.ncbi.nlm.nih.gov).
- Possess anti-inflammatory and antiplatelet properties, which could be valuable for cardiovascular health (pmc.ncbi.nlm.nih.gov).
However, most of these findings are based on in vitro (test tube) or animal studies. Robust clinical evidence in humans is not yet available, and the bioactive doses needed for therapeutic efficacy may differ from those in household or cosmetic use.
Expert voices within Thai traditional medicine have long advised a balanced approach. A Thai practitioner and educator in traditional herbal remedies points out that while som poi’s saponin-rich content makes it highly effective for cleansing hair, overuse—particularly of pod-based shampoos—can cause eye irritation or dryness, especially in children. “Just because something is natural does not mean it is always gentle for everyone,” this expert explains. “Each person’s body is different. Use all herbs carefully, respect their power, and consult healthcare professionals if any reaction occurs.” (phar.ubu.ac.th)
From a scientific standpoint, pharmacologists caution that saponins, while beneficial in moderate amounts, may be toxic at very high doses. Animal studies indicate a wide margin of safety in conventional use, with estimated LD50 (lethal dose for 50% of subjects) for som poi extracts being relatively high. Nonetheless, researchers consistently recommend further toxicity and side-effect studies before encouraging concentrated extracts for widespread oral consumption, particularly for children, pregnant women, or those with chronic conditions (pmc.ncbi.nlm.nih.gov; pmc.ncbi.nlm.nih.gov).
The overlap between tradition and innovation is especially pronounced when considering the directions of current research. Clinics and community health projects across Thailand are exploring som poi’s role in holistic wellness—integrating herbal wisdom with lifestyle interventions for metabolic disorders, or encouraging the use of plant-based cleansers over synthetic alternatives for those with sensitive skin. There are even efforts to develop value-added products: anti-dandruff shampoos, antibacterial soaps, and even herbal pastes for minor wounds—all rooted in the heritage of som poi, but guided by modern quality standards (disthai.com; phar.ubu.ac.th).
In many ways, som poi’s journey reflects the broader story of Thai herbal medicine. Ancient texts and contemporary scientific literature reveal a sophisticated understanding of plant chemistry, dosage, and preparation, often more nuanced than assumed by outsiders. The modern scientific method is catching up, validating age-old practices while paving the way for new discoveries that may benefit not only Thailand, but the wider world.
At the same time, the revival of som poi and other native remedies carries a reminder: traditional medicines are not always “one-size-fits-all” solutions, nor are natural products inherently safe for indiscriminate use. As with any health intervention, consultation with healthcare professionals remains essential, especially when dealing with chronic illness, pregnancy, or ongoing medication.
For the health-conscious Thai public, the actionable lesson is clear: there is value in reconnecting with local herbal wisdom, but the wisest path is to blend it with careful inquiry and respect for scientific rigor. Using som poi as a gentle shampoo, a cooling decoction, or a culinary souring agent poses little risk for most people, provided any allergies or prior sensitivities are considered. Those wishing to try more concentrated extracts for therapeutic purposes should seek guidance from licensed practitioners.
As Thailand looks to the future, som poi stands as a testament to the nation’s ability to harmonize tradition and innovation. Whether used as a symbol of renewal during Songkran, a part of family beauty rituals, or an inspiration for new health products, Acacia concinna continues to offer its gifts—bridging old and new, village and city, healer and scientist.
For more information on the history, preparation, and scientific study of som poi, readers may visit:
- PROSEA Plant Resources: Acacia concinna
- Phytochemical and Antioxidant Study – Plants (MDPI)
- Biomedical Characterization – Molecules (MDPI)
- เขตข้อมูลสมุนไพรไทย มหาวิทยาลัยอุบลราชธานี
- ข้อมูลสมุนไพร ส้มป่อย – ดิสไทย
Disclaimer: This article is for informational and educational purposes only. The use of traditional remedies should be approached with care, and individuals are strongly encouraged to consult qualified healthcare professionals before starting any form of herbal therapy, especially when pregnant, breastfeeding, or managing chronic health conditions.