For centuries, the slender, finger-like fruit known as ดีปลี (Dipli)—or long pepper to the wider world—has been valued in Thai kitchens and medicine cabinets alike. Revered for its spicy-hot kick and its potent medicinal reputation, Dipli has traveled the journey from sacred ritual and home remedy to the laboratory bench, where new research is validating some ancestral claims while raising important questions about its safety and efficacy. Today, this unassuming fruit—harvested just before ripening from the Piper retrofractum vine—stands at a crossroads between tradition and science, inviting curious minds and health enthusiasts to discover its story.
In Thailand, good health is often built on a foundation of plants and spices passed down through generations. Dipli occupies a particularly valued place. Its fruit—harvested while still green and later dried to a deep reddish hue—is called ดีปลี, with a host of local names reflecting its importance in various regions: ดีปลีเชือก, ประดงข้อ, ปานนุ, พิษพญาไฟ, and ปีกผัวะ. In Buddhist ceremonies, Dipli has been known to find a place among herbal mixtures used by monks and healers, and it remains a perennial ingredient in northern and central Thai folk remedies, not to mention certain curries and healing teas (StuartXchange; Gernot Katzer’s Spice Pages; thaifooding.com). The plant itself—Piper retrofractum, a relative of black pepper and betel—sprawls across home gardens in the central provinces of Kanchanaburi, Ratchaburi, Phetchaburi, and Chanthaburi. Local knowledge has long held that Dipli stimulates digestion, eases coughs, fights fevers, soothes asthma symptoms, and helps with conditions as wide-ranging as hypertension, rheumatism, and even male vitality (ResearchGate; PDF - Manoa).
But tradition is only half the story. Over the past decade, a series of scientific investigations—many conducted in neighboring Southeast Asian countries—has started to unravel Dipli’s chemical secrets. The spicy bite of long pepper comes from alkaloid compounds such as piperine, which is also present in black pepper but at higher concentrations in Dipli (Wikipedia). Laboratory studies have shown that these bioactive compounds possess a range of pharmacological activities: they can act as antioxidants, antimicrobials, anti-inflammatories, and possibly even cancer-preventive agents (ScienceDirect; ResearchGate; PMC - NIH).
For instance, a 2020 study examined the antimicrobial properties of Dipli fruit extracts and found that methanol extracts could inhibit the growth of several drug-resistant bacteria and fungi—including Staphylococcus aureus, Escherichia coli, and Candida albicans—common culprits in both human and animal infections. The study, which used dried Dipli fruits commonly found in Thai herbal shops, reported that certain extracts were able to suppress the growth of these pathogens even at relatively low concentrations. This raises intriguing possibilities for Dipli as an adjunct in the fight against antibiotic-resistant microbes, both in traditional therapies and modern applications (PMC Article). For Thais accustomed to using herbal tonics for minor ailments, such findings serve as a modern echo of ancient wisdom.
Dipli’s effects on inflammation, cholesterol, and gastric health are also being explored. Early stage in vitro and animal studies suggest that certain extracts may soothe inflamed tissues and have a gastroprotective effect, possibly helping to prevent ulcers and lower cholesterol levels (ResearchGate review). In traditional Thai medicine, these properties align with Dipli’s use to treat wind-related illnesses—conditions believed to stem from internal imbalances manifesting as bloating, colds, and rheumatic aches.
But what about safety, and what happens when ancient tradition meets the rigor of contemporary toxicology? Here, the story of Dipli becomes more complex, especially when considering its main active compound, piperine. Toxicological studies, primarily conducted on animals, suggest that very high doses of isolated piperine (hundreds of milligrams per kilogram of body weight) can be harmful—causing convulsions, respiratory distress, and even death in laboratory mice and rats. At lower but prolonged doses, piperine has been shown to affect reproductive health in male rats, temporarily suppressing sperm counts and affecting testicular function, with most effects reversing after the animals returned to a normal diet (PMC Article on Safety). No such adverse effects have been reliably demonstrated in humans at traditionally consumed levels through food and standard herbal remedies, but caution is advisable, especially for individuals considering high-dose extracts or supplements.
Another point of caution for Dipli’s potential use in modern health: piperine is a well-known “bio-enhancer.” In both animal and human studies, even small amounts (as little as 20 mg per day) have been shown to increase the absorption and effectiveness of various pharmaceutical drugs, from antibiotics to sedatives to antihistamines (PMC Safety Report). For some, this may improve medication efficacy, but for others, it could raise the risk of drug interactions or side effects. Thais who are taking prescription medications—common among elders with hypertension, diabetes, or heart conditions—should consult healthcare professionals before using Dipli as a medicine, particularly concentrated extracts.
Despite these caveats, the culinary uses of Dipli are generally considered safe by the Thai Food and Drug Administration. In fact, the inclusion of Dipli in herbal blends for “wind symptoms,” digestive complaints, and postpartum tonics is common in community pharmacies and local “mor baan” (village healers) clinics, with no significant reports of toxicity when used in moderation (ScienceDirect; NIH - PMC). Traditionally, Dipli is rarely consumed in isolation but as a component of complex herbal blends, which may mitigate any risks associated with higher dosages of individual compounds.
This intersection of tradition and modern science is reflected in Thailand’s growing phytotherapy research sector. Thai research groups, working independently and sometimes in collaboration with regional partners in Indonesia and Malaysia, are developing new applications for Dipli. These include natural food preservatives (leveraging its antimicrobial effects), herbal teas for gastrointestinal health, and topical preparations for skin conditions (PMC - StuartXchange; PNAS). Some studies even suggest that Dipli extracts might someday contribute to the development of novel antibiotics or antifungal medications. Still, before any such dreams are realized, more clinical trials in humans are needed to confirm efficacy, safety, and appropriate dosing.
The cultural roots of Dipli run deep in Southeast Asian cuisine and medicine. In northern Thailand, it was often ground with galangal and other roots to create “Nam Maakham Piak,” a warming, digestive tonic for chilly mountain climates and festival seasons. In southern cuisine, Dipli finds its way into massaman curries or as a spicy accent in herbal pork sausages. Folk healers, drawing on Buddhist and animist traditions, would prepare a decoction of Dipli for mothers recovering from childbirth or as a remedy for fevers in children. For today’s Thai families, these rituals and flavors connect the present to a living heritage.
Looking forward, the potential of Dipli lies not just in rediscovering ancient knowledge, but in responsibly translating it for the needs of modern Thai society. As the country faces rising antimicrobial resistance and an aging population turned increasingly toward personalized natural health, Dipli may offer both wisdom and opportunity—but only with due attention to safety and quality control. The experience of the West, where herbal supplements are widely sold but often poorly regulated, serves as a cautionary tale. Ensuring that Dipli products are standardized, free of contaminants, and labeled appropriately will be essential as demand grows.
For Thai readers exploring Dipli as a health supplement or culinary spice, several practical steps are advisable:
- Use Dipli in moderation as part of a balanced diet, favoring traditional preparations over concentrated extracts, unless directed by a healthcare provider.
- Be cautious if taking prescription medications or if pregnant, as Dipli’s active compounds can interact with drugs and may not be safe in high doses.
- Seek advice from healthcare professionals—including licensed Thai traditional medicine practitioners—before starting any new herbal regimen.
- Purchase Dipli and its products from reputable sources to ensure quality and authenticity.
Most importantly, remember that while the healing potential of Dipli is supported by tradition and increasingly by science, no herbal remedy should replace professional medical care for serious conditions.
Dipli stands as a symbol of the dynamic interplay between heritage and innovation—proof that traditional Thai wisdom can inform, inspire, and refine the future of healthcare. Its journey from jungle vine to spice rack, from temple offering to research laboratory, is far from over. As science continues to shed new light on this ancient fruit, Thai households can take pride in a cultural treasure that bridges the gap between old and new, heart and mind.