Chinese Pond Turtle (Mauremys reevesii / Chinemys reevesii) as a Dietary Supplement and Traditional Medicine Ingredient
1. Identity and Nomenclature
Scientific Names and Taxonomy
The Chinese pond turtle, commonly known also as the Chinese three-keeled pond turtle or Reeves' turtle, is a species of turtle in the family Geoemydidae, a family which was formerly called Bataguridae. The species includes the forms Chinemys megalocephala Fang, 1934, Geoclemys grangeri Schmidt, 1925, and Damonia unicolor Gray, 1873, which have on occasion been considered as valid species or subspecies, but have in recent years been treated consistently as synonyms of reevesii. The currently accepted binomial is Mauremys reevesii (Gray, 1831), though the synonymous name Chinemys reevesii remains widely used in the pharmacological and food science literature.
In Chinese medicine nomenclature, the dried shell product is known under two closely related names: Guiban (龟板 or 龟甲) or Guijia (龟甲), depending on whether only the plastron or both the plastron and carapace are included. The formal pharmaceutical designation Testudinis Carapax et Plastrum (TCP), often referred to as "guijia" in Chinese, is the dried carapace and plastron from Chinemys reevesii (syn. Mauremys reevesii Gray, 1831). The Pharmacopoeia of the People's Republic of China (2020 edition) lists TCP as salty and sweet in taste and slightly cool in nature, passing through the liver, kidney, and heart channels.
The Chinese herb Gui Ban is the plastron of the Chinese pond turtle (also called Reeves' turtle — Chinemys reevesii (Gray)), the plastron being the part of the shell on the underside of the turtle that protects the inner organs.
Natural Range and Habitat
The Chinese pond turtle is a commercially valuable and protein-rich edible aquatic species native to Hong Kong, China, Taiwan, Japan and Korea. It is semiaquatic, and basks in the sun on rocks or logs; it can usually be found in marshes, relatively shallow ponds, streams, and canals with muddy or sandy bottoms.
Common Commercial Forms and Preparations
The animal's different anatomical parts each yield distinct medicinal and food preparations:
- Dried shell (plastron and/or carapace): The primary pharmacopeial material. Both Testudinis Carapax et Plastrum (TCP, carapace and plastron of Chinemys reevesii) and Trionycis Carapax (carapace of Trionyx sinensis) were consumed as important animal-derived medicinal materials in Traditional Chinese Medicine. They are usually subjected to a vinegar-quenched process, and these highly processed products are more widely administered in clinical practice to nourish Yin and subdue Yang.
- Shell gelatin (Guiban Jiao / Tortoise shell glue): Tortoise shell glue is renowned in traditional medicine as a hematinic and hemostatic agent, historically employed as a vital tonic.
- Muscle/meat hydrolysates and peptide isolates: The bioactivity of Chinese pond turtle muscle proteins and their enzymatic hydrolysates has been investigated for antioxidant, antidiabetic, and cytotoxic activities. Muscles are hydrolysed using proteolytic enzymes such as Alcalase, Flavourzyme, trypsin, and bromelain, and the degrees of hydrolysis measured.
- Skin-derived collagen: During tortoise shell glue production, turtle skin emerges as a major byproduct, representing a rich yet underutilized source of collagen.
- Culinary preparations: In traditional medicine, every last part of the turtle is consumed, including the turtle meat, as well as the skin, heads, eggs, shells and even blood, urine, and bile.
Gui Ban is commonly adulterated with plastrons from other turtle species. Research has identified plastrons of Ocadia sinensis (Chinese stripe-necked turtle), Chelonia mydas (green sea turtle), Lepidochelys olivacea (olive ridley sea turtle), and Trachemys scripta elegans (red-eared slider) as counterfeit substitutes. Authentic Gui Ban from Mauremys reevesii can be distinguished by its characteristic 12 shield plates with purplish-brown radiating lines on the ventral surface, and the saw-tooth interlocking pattern of the 9 underlying bone plates visible on the interior surface.
2. Traditional and Historical Use
Historical Depth and Cultural Context
The first Chinese pharmacopeia, the Compendium of Materia Medica, recorded 440 years ago, documented the significant medicinal value of C. reevesii. Use stretches back considerably further. Alongside the Chinese softshell turtle, it is one of the two most commonly found species used for divination that have been recovered from Shang dynasty sites. Chinese pond turtle has been considered a dietary remedy for prolonging the lifespan since ancient times.
The Chinese turtle trade is the primary threat to endangered turtle populations throughout Asia, primarily because of the long tradition of consuming turtles in China. Practitioners of Traditional Chinese Medicine promote nutritional and medicinal benefits from eating turtles, especially those made from hardshell species.
TCM Theoretical Framework
In Traditional Chinese Medicine, Gui Ban belongs to the category of "Tonic herbs for Yin Deficiency." Tonic herbs are used for patterns of Deficiency, when one lacks one of the "Four Treasures" (Qi, Blood, Yin, and Yang). Yin tonics have a heavy, moist nature. They either nourish the Kidneys and Liver or moisten the Lungs and Stomach.
In TCM material medica classifications, tortoise shell (Guiban) is described as: nourishes yin, subdues yang, strengthens tendons and muscles, cools blood, and supplements blood. TCP's main pharmacopoeial indications include nourishing yin and latent yang, invigorating the kidneys and strengthening bone, nourishing blood and tonifying the heart, and reinforcing the meridian and stopping collapse.
A classical teaching notes that Gui Ban excels at nourishing while Bie Jia (soft-shelled turtle shell) excels at attacking and breaking down accumulations. For long-term Yin tonification, Gui Ban is preferred; for stubborn Deficiency Heat or abdominal masses, Bie Jia is the better choice.
Traditional Preparations and Formulas
Guiban is most celebrated as a component in classic herbal formulas, such as Guiban Tang (Turtle Shell Decoction) and Zuo Gui Wan (Restore the Left Pill), where it is often paired with herbs like rehmannia, peony, and angelica. These combinations enhance its nourishing effects, allowing for a synergistic approach in restoring balance and vitality.
Turtle shell pill (TSP) is a traditional Chinese medicine formula from the Golden Chamber, written by Eastern Han Dynasty physician Zhang Zhongjing, composed of turtle shell glue, gelatin, honeycomb, saltpeter, and another 23 types of medicinal compounds.
Primary conditions or symptoms for which Gui Ban may be prescribed by TCM practitioners include: night sweats, vertigo, tremors, amnesia, hypertension, chronic lower back pain, retarded growth in children, abnormal uterine bleeding, anxiety, insomnia, sores, and ulcers.
The treatment of flaccidity and weakness of the loins and feet (alternatively described as weakness of the lower back and limbs) corresponds to treatment of heaviness and weakness in the limbs from the Shennong Bencao Jing; the treatment of uterine bleeding corresponds to "red leakage," and there is common mention of closure of the fontanel, connecting the ancient and modern uses.
The eggs, blood, and bile of turtles are all added to wine to provide particular cures, whereas the skin and head are eaten alone. In traditional practices, the turtle's shell and meat are believed to possess unique restorative properties, and they have been incorporated into well-known formulas such as "Gui Ling Gao," a jelly dessert prized for its supposed cooling and detoxifying effects.
3. Key Constituents and Active Compounds
Plastron and Shell Composition
Existing evidence shows that Plastrum testudinis acts as an anti-inflammatory substance with significant antioxidant properties, containing bioactive components such as steroids (cholesterol, 4-cholesten-3-one, and cholesterol myristate), fatty acids (stearic acid and palmitic acid), and esters (methyl palmitate, ethyl palmitate, methyl stearate, and ethyl stearate), which could promote the proliferation and growth of bone cells. Steroids are involved in osteoblast proliferation via the NF-κB signaling pathway, while fatty acids can promote alkaline phosphatase (ALP) activity.
The content of 27 amino acids, 22 amino acid derivatives, and 18 small peptides in the decoctions of TCP and two substitute preparations have been absolutely quantified, constituting up to tens of milligrams per 10 g of tortoise shell.
Muscle Protein and Peptide Composition
The muscle of C. reevesii is rich in protein and has a balanced amino acid composition and a rich content of unsaturated fatty acids, especially high levels of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Additionally, its muscle contains essential minerals and trace elements, among which iron, zinc, calcium, and selenium are all relatively high.
In hydrolysis research, Chinese pond turtle muscles have been hydrolysed using four proteolytic enzymes (Alcalase, Flavourzyme, trypsin, and bromelain), and high-performance liquid chromatography (HPLC) has been conducted to explore the amino acid profiles and molecular mass distribution of the hydrolysates.
Skin Collagen
Collagen from Chinemys reevesii skin has been obtained using both acid and enzymatic extraction methods. The composition, structure, and physicochemical characteristics have been determined using SDS-PAGE, HPLC, circular dichroism spectrometry, differential scanning calorimetry, and scanning electron microscopy. Acid-soluble collagen (ASC) and enzyme-soluble collagen (PSC) extraction yields were 24.50% and 51.68% respectively. Both ASC and PSC comprised α1 and α2 chains and exhibited a distribution pattern typical of Type I collagen. The content of glycine in ASC and PSC was the highest, at 370.17 and 387.75 residues per 1000 amino acid residues, respectively.
Incidents involving diseases such as bovine spongiform encephalopathy (BSE) and foot-and-mouth disease (FMD) have eroded public trust in collagen sourced from terrestrial animals. However, few studies have been conducted on collagen sourced from aquatic animals regarding disease-related safety implications, suggesting they may represent a more secure alternative.
4. Mechanisms of Action
Antioxidant Mechanisms
Chinese pond turtle peptide (CPTP) remarkably increased antioxidant enzyme activities and diminished peroxide product accumulation. Research has investigated the Nrf2/Keap1 signaling pathway as a key mechanistic target. Peptide extracted from soft-shelled turtle not only possessed superior antioxidant activity in vitro but also could regulate the Nrf2-mediated signaling pathway in mice.
Bone and Musculoskeletal Mechanisms
Research implies that plastrum testudinis extracts (PTE) promote the proliferation and osteogenic differentiation of rat bone marrow-derived mesenchymal stem cells (rBMSCs) by upregulating p38 MAPK, STE20, and IGF1R, and downregulating TRAF6 expression. Separate network pharmacology and experimental validation research reported that PT downregulates the expression of osteoclast-specific genes, including C-FOS, TNF, and BDNF, in the MAPK signaling pathway, thus exerting a suppressive effect on osteoclastogenesis.
Hepatic Fibrosis Mechanisms
Hepatic fibrosis is a wound-healing response to a variety of chronic stimuli, characterized by the excessive synthesis of extracellular matrix proteins by hepatic stellate cells and the eventual development of hepatic cirrhosis. Turtle shell pill (TSP) is a common traditional Chinese medicine used for preventing and treating hepatic fibrosis and early hepatic cirrhosis. In a CCl4-induced hepatic fibrosis rat model, a novel turtle shell decoction had similar effects to the original turtle shell pill on improving liver functions in rats, including a decrease in serum ALT and AST concentrations and increased albumin content.
Peptides of less than 6 kDa derived from turtle shells are considered effective components for anti-liver fibrosis activity. The protein of turtle shells has important potential as a source of bioactive peptides which may play a role as ingredients in functional foods.
Anti-inflammatory Mechanisms (Intervertebral Disc)
Plastrum testudinis exerts protective effects against bone diseases such as intervertebral disc degeneration (IDD). Despite its effectiveness, the molecular mechanisms underlying the effects of PT on IDD remain unclear. A 2023 PMC study used bioinformatic analysis combined with experimental verification (including GO and KEGG pathway enrichment analyses) to investigate anti-IDD mechanisms. PT has protective effects against bone disorders such as osteoporosis and fracture, and may be beneficial for IDD via its anti-inflammatory and cell proliferation-promoting effects on annulus fibrosus cells.
5. Scientific Evidence by Area of Use
5.1 Bone Health and Osteoporosis
Extracts from plastrum testudinis are active compounds that have been used to treat bone diseases in traditional Chinese medicine for thousands of years. Earlier studies demonstrated effects on glucocorticoid-induced osteoporosis (GIOP) both in vivo and in vitro. In a representative in vitro study, rBMSCs were treated with medium (control), PTE, osteogenic induction, and a combination of PTE and osteogenic induction over a 21-day period; PTE significantly promoted rBMSCs osteogenic differentiation and mineralisation after 21 days.
Plastrum testudinis extracts (PTE) were shown to prevent and treat GIOP in vivo; however, PTE alone are seldom used clinically. A study explored the synergistic effect of alendronate (ALN) and PTE in treating GIOP of the rat spine. Sprague-Dawley rats were randomly assigned to vehicle, GIOP, ALN, and ALN+PTE groups, further divided into dexamethasone intervention and withdrawal phases. Bone mass, microarchitecture, biomechanics, bone-turnover markers, and histomorphology were evaluated. The combination of ALN+PTE improved bone quantity and quality, bone strength, and bone turnover, and mitigated histological damage during glucocorticoid intervention and withdrawal.
Current studies have demonstrated that the extracts of Plastrum testudinis have protective effects against bone diseases including senile osteoporosis and intervertebral disc degeneration, with research publications covering the period 2016 to 2023.
Evidence strength: All published research to date consists of in vitro cell studies and animal model experiments (rodents). No clinical (human) trials have been identified in the peer-reviewed literature. The evidence is preliminary and preclinical.
5.2 Hepatic Fibrosis
Turtle shell pill (TSP) has been approved by the Chinese State Food and Drug Administration for the clinical prevention and treatment of hepatic fibrosis and early hepatic cirrhosis, confirming that it has obvious anti-fibrosis effects. However, TSP is a complex multi-ingredient formula and attributing effects specifically to the turtle shell component alone is methodologically difficult.
A decoction of turtle shell for anti-fibrosis combined with stronger neo-minophagen C (a glycyrrhizin preparation) could significantly improve clinical efficacy, liver fibrosis indexes, and liver function indices in chronic hepatitis B. This clinical combination study, while referenced in TCM databases, does not isolate the contribution of the turtle shell component.
Evidence strength: There is regulatory approval within China for a multi-ingredient formula containing turtle shell for hepatic fibrosis/cirrhosis. In vitro and animal studies of isolated peptides show anti-fibrotic activity. No controlled clinical trials isolating turtle shell extracts alone have been identified.
5.3 Antioxidant Activity and Anti-aging
A published study (PMC9355154, Frontiers in Nutrition, 2022) assessed the antioxidant activities and antiaging potential of Chinese pond turtle peptide (CPTP) using a Drosophila melanogaster model. CPTP exhibited excellent antioxidant capability in vitro with IC50 values of 3.31, 1.93, and 9.52 mg/mL for DPPH, ABTS, and hydroxyl radical scavenging, respectively. In vivo, 0.8% CPTP significantly extended the mean and median lifespan of female flies by 7.66 and 7.85%, followed by enhanced resistance to oxidative and heat stress.
In collagen peptide research, ultrasound pretreatment-assisted enzymatic hydrolysis (UPH) of Chinemys reevesii skin showed higher antioxidant activity than conventional enzymatic treatment. At 5 mg/mL, it displayed an ABTS radical scavenging rate of 87.59%, a DPPH scavenging rate of 53.37%, and the highest reducing power.
Evidence strength: All antioxidant/anti-aging studies conducted on CPTP and skin collagen hydrolysates are in vitro assays or invertebrate (Drosophila) models. There are no human trials. The evidence is preliminary, with no established clinical applicability.
5.4 Antidiabetic Activity
Chinese pond turtle hydrolysates contain high content of antioxidant components and antidiabetic activities. The bioactivity of Chinese pond turtle muscle proteins and their enzymatic hydrolysates has not received much attention, and studies aim to investigate antioxidant, antidiabetic, and cytotoxic activities in vitro. Bioactive peptides derived from many food proteins using enzymatic proteolysis and food processing have a positive impact on the prevention of cardiovascular diseases and diabetes, the biggest causes of death globally.
Evidence strength: Exclusively in vitro. There are no animal model or human clinical studies specifically on antidiabetic effects of Chinemys reevesii products. Evidence is at the earliest exploratory stage.
5.5 Aplastic Anemia and Blood Disorders
One evaluation involved 300 patients recruited during a 27-year period and treated with Chinese herbal formulas. All formulas contained donkey skin gelatin, rehmannia, and licorice; for patients with the traditional diagnosis of hyperactivity of yang and deficiency of yin, tortoise shell, turtle shell, stellaria, picrorrhiza, and lycium bark were also included. While cure rates were relatively low, improvement rates were described as high; in the case of yin deficiency and yang hyperactivity, 77% of patients were reported to respond to this treatment method.
Evidence strength: These are historical, uncontrolled, multi-ingredient TCM case series, not randomized controlled trials. M. reevesii was one component among many; the independent contribution of turtle shell cannot be isolated. Evidence is anecdotal and limited in methodological quality.
5.6 Neurological and Other Applications
Published research (referenced in a 2025 Frontiers in Pharmacology metabolomics study) has investigated Plastrum testudinis extracts in relation to Parkinson's disease, Alzheimer's disease, acute promyelocytic leukemia, beta-thalassemia and sickle cell anemia, and skin wound healing, with publications spanning 2013–2024. These studies are referenced but represent distinct areas of preclinical research rather than established clinical evidence. Each of these areas remains at the in vitro or animal model stage.
6. Body Systems and Health Areas Associated With Chinese Pond Turtle
- Skeletal system: Plastrum testudinis is one of the most widely used traditional Chinese medicines for treating skeletal disorders. Osteoporosis, bone fracture healing, and intervertebral disc degeneration are the areas most studied preclinically.
- Hepatic system: Turtle shell pill is a common traditional Chinese medicine used for preventing and treating hepatic fibrosis and early hepatic cirrhosis.
- Cardiovascular and hematological systems: Tortoise shell glue is renowned in traditional medicine as a hematinic and hemostatic agent. TCM applications have historically included uterine bleeding and aplastic anemia within complex formulae.
- Metabolic/endocrine system: Antidiabetic and lipid-modulating activity has been studied in vitro via peptide hydrolysates.
- Antioxidant/aging: Chinese pond turtle is a traditional nourishing food with high nutritional value and bioactivity and has been considered a dietary remedy for prolonging the lifespan since ancient times.
- Nervous system: TCM formulas containing Gui Ban have historically been applied to tremors, vertigo, and insomnia, and preclinical research has begun exploring Parkinson's and Alzheimer's disease models.
7. Dosage Forms and Reported Dosages
Preparation of Gui Ban involves extracting the carapace and plastron, boiling in order to clean thoroughly, and then drying. In the TCM context, the dried shell is typically decocted in water. Main actions attributed to Gui Ban in TCM include: nourishing the Yin and holding down the Yang, strengthening the Kidneys and strengthening the bones, cooling the Blood and stopping uterine bleeding, nourishing the Heart, and promoting healing.
In scientific research settings, the following dosages and preparations have been reported:
- CPTP in Drosophila lifespan study: In vivo, 0.8% of CPTP significantly extended the mean and median lifespan of female flies by 7.66 and 7.85%. This concentration was incorporated into the fly medium; no human equivalent dose can be extrapolated.
- Collagen peptide antioxidant assay: At 5 mg/mL, ultrasound pretreatment-assisted collagen hydrolysates displayed an ABTS radical scavenging rate of 87.59% and a DPPH scavenging rate of 53.37%.
- Clinical formula dosage context: Gui Ban appears in classical formulas such as "Rehmannia Bolus of Six Herbs Plus Anemarrhena and Phellodendron" (Zhi Bai Di Huang Wan), combined with Rhizoma Anemarrhenae and Radix Rehmanniae.
No standardized or pharmacopoeially defined dosage specifically for Chinemys reevesii-derived dietary supplements (outside of full TCM decoction practice) has been identified in the peer-reviewed literature reviewed. Clinical dosage ranges for Gui Ban in Traditional Chinese Medicine decoctions as reported in Chinese herbal databases typically fall in the range of 9–30 g per day in decoction, but this is the TCM prescription context, not a validated supplement dose.
8. Safety Considerations and Interactions
Traditional Contraindications
Because it is cold and heavy in nature, Gui Ban is not suitable for people with cold or weak digestion in TCM practice. Contraindications in TCM practice include pregnancy and individuals with Cold and Dampness of the Spleen.
Adulteration and Species Substitution
Testudinis Carapax et Plastrum (TCP) is an animal-based traditional Chinese medical material whose decoction or extract possesses multiple pharmacological effects. However, other species-sourced substitutes are sometimes used in the market, potentially impairing the quality and effectiveness of TCP medications. Gui Ban is commonly adulterated with plastrons from other turtle species. Research has identified plastrons of Ocadia sinensis, Chelonia mydas, Lepidochelys olivacea, and Trachemys scripta elegans as counterfeit substitutes.
Salmonella Risk
In the United States, general FDA rules ban commercial importation of turtles under 4 inches in carapace length to mitigate Salmonella risks. This concern relates primarily to live animals and fresh/unprocessed products rather than dried, heat-processed TCM preparations.
Heavy Metals and Shell Mineral Composition
The shell of Chinemys reevesii contains a broad mineral profile. Studies have compared the 22 mineral elements in shells from official animals and their counterfeits. Depending on the sourcing environment (wild vs. farmed, and geographic region), accumulation of heavy metals in bone/shell tissue is a recognized concern with aquatic species generally; however, no specific quantified safety data for TCP heavy metal content was identified in the sources reviewed.
Conservation and Regulatory Status
Mauremys reevesii is listed in CITES Appendix III (China). Over the past 30 years, the species has disappeared from at least half its original area of occurrence as a result of targeted collection, and collection pressures continue. Artificially bred Chinemys reevesii are explicitly excluded from endangered species protection categories, as their large-scale commercial farming in China has ensured sustainable populations. This legal and ecological status designates them as legitimate, high-quality raw materials for tortoise shell glue production, distinguishing them from wild protected species.
Over the five-year period from 1990 to 1995, 13 traditional Chinese medicine factories consumed 430 tons of C. reevesii plastrons. Since 2017, China's annual freshwater turtle production has been maintained at more than 45,000 tons, with farmed production reaching 53,900 tons in 2022, making China the largest consumer of C. reevesii globally.
Many Asian turtle farms, particularly in China exporting species like Mauremys reevesii, have faced scrutiny for failing to meet CITES captive-breeding standards, with exports often requiring ranching permits for head-started wild juveniles rather than true closed-cycle breeding.
Combination with Pharmaceutical Drugs
Clinically, plastrum testudinis extracts (PTE) alone are seldom used to treat bone diseases; researchers have explored whether PTE acts synergistically with alendronate (ALN) to counter glucocorticoid-induced osteoporosis in rat models. No published human pharmacokinetic or drug-interaction studies on Chinemys reevesii products in combination with Western pharmaceuticals were identified in the literature reviewed.
References
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