Glucono Delta Lactone Powder
Also known as: GDL, Glucono-δ-lactone, gluconolactone, Glucono delta lactone
Overview
Glucono delta lactone (GDL) is a naturally occurring lactone derived from gluconic acid, commonly found in foods like wine and honey. It is widely utilized as a food additive for its acidifying properties and as a coagulant, particularly in tofu production. Additionally, GDL is incorporated into cosmetic formulations, primarily functioning as a skin conditioner and exfoliant. Its key characteristic is its slow hydrolysis in aqueous solutions, which gradually releases gluconic acid and lowers pH, making it valuable for controlled acidification in various applications. Research on GDL encompasses toxicology, food technology, and emerging clinical studies on its dermatological effects. While its toxicological profile is well-established, clinical evidence for all its benefits is still developing.
Benefits
GDL offers several evidence-based benefits, particularly in skin health and food quality. For skin health, a randomized, double-blind, placebo-controlled trial demonstrated that oral GDL supplementation (2000 mg/day) significantly improved skin barrier function by reducing transepidermal water loss, increased skin elasticity by 6.2% at 2 months and 5.4% at 6 months, and enhanced facial lightness by 1.6% at 6 months. This study also indicated anti-inflammatory and photoprotective effects, as it suppressed UVB-induced erythema and pigmentation. In food applications, GDL dipping combined with in-pack pasteurization has been shown to delay starch retrogradation in rice noodles, thereby improving their texture and extending shelf life. Toxicological studies in rodents further support its safety, showing no adverse effects at high doses (up to 340 mg/kg-day for 29 months) and no reproductive or developmental toxicity at doses up to 560-780 mg/kg-day, establishing a strong safety profile.
How it works
Glucono delta lactone (GDL) primarily functions through its gradual hydrolysis in aqueous solutions, which releases gluconic acid and consequently lowers the pH. This controlled acidification is central to its various applications. In the skin, this acidifying effect is believed to enhance barrier function and reduce inflammation, potentially by modulating the skin's surface pH and influencing inflammatory pathways. In food systems, the acidification process delays starch retrogradation by altering the molecular interactions of starch, which helps to improve texture and extend the shelf life of products. The slow and sustained release of acid makes GDL a versatile agent for controlled pH adjustments in biological and food matrices.
Side effects
Overall, Glucono delta lactone (GDL) is considered safe for human consumption and topical use at typical doses. Extensive animal studies have shown no significant toxicity or reproductive harm, even at high doses, with a No Observed Adverse Effect Level (NOAEL) exceeding 340 mg/kg-day. For cosmetic applications, gluconolactone (a closely related compound) is deemed safe at concentrations commonly used in formulations, with minimal reports of irritation. There are no significant drug interactions or contraindications that have been reported for GDL. The comprehensive toxicological data available supports a favorable safety profile, indicating that adverse effects are rare when used within recommended guidelines. Specific risk factors for adverse reactions are not well-documented, suggesting a broad safety margin for most individuals.
Dosage
For clinical benefits related to skin health, a dosage of 2000 mg/day of oral GDL was used in a study for 6 months, demonstrating measurable improvements. Toxicological studies indicate that GDL is safe at doses significantly higher than typical human consumption levels. In cosmetic formulations, gluconolactone is commonly applied topically at concentrations ranging from 1% to 8%. There are no specific cofactors required for GDL's action, as its absorption and hydrolysis occur naturally within the body and in topical environments. While specific upper limits for human consumption are not explicitly defined beyond the safety data from animal studies, the high NOAEL suggests a wide safety margin. Dosage for food applications varies depending on the desired effect, such as acidification or coagulation, and is typically regulated by food safety authorities.
FAQs
Is GDL safe for long-term use?
Yes, animal studies and cosmetic safety assessments support the long-term safety of GDL at typical doses and concentrations, showing no significant toxicity or reproductive harm.
How quickly does GDL improve skin?
Improvements in skin elasticity and barrier function were observed within 2 months of oral GDL supplementation, with continued benefits noted at 6 months in clinical studies.
Can GDL be used topically and orally?
Yes, GDL is versatile and is used both as a food additive for oral consumption and as an ingredient in topical cosmetic products for skin benefits.
Does GDL have antimicrobial effects?
GDL's acidifying property can inhibit microbial growth in foods. While its direct antimicrobial effects on skin microbes are less studied, its pH-lowering action can create an unfavorable environment for some pathogens.
Research Sources
- https://www.epa.gov/sites/default/files/2019-08/documents/support_document_for_proposed_designation_of_d-gluconic_acid_.delta_.-lactone.pdf – This EPA support document summarizes long-term rodent toxicology studies, indicating no adverse effects of GDL at doses up to 340 mg/kg-day for 29 months, and no reproductive or developmental toxicity at doses up to 780 mg/kg-day. These high-quality data establish a favorable safety profile for GDL.
- https://pubmed.ncbi.nlm.nih.gov/29431785/ – This randomized, double-blind, placebo-controlled trial with 40 healthy male volunteers demonstrated that oral GDL (2000 mg/day) significantly improved skin barrier function, increased skin elasticity, and enhanced facial lightness over 6 months. It also showed photoprotective effects by suppressing UVB-induced erythema and pigmentation.
- https://pmc.ncbi.nlm.nih.gov/articles/PMC9162945/ – This experimental study showed that GDL dipping combined with in-pack pasteurization effectively delayed starch retrogradation in rice noodles. The findings suggest that GDL can improve the texture and extend the shelf life of food products through its acidifying properties.
- https://www.cir-safety.org/sites/default/files/TR_Glycolactones_032022.pdf – This safety assessment by the Cosmetic Ingredient Review (CIR) Expert Panel concludes that gluconolactone (a closely related compound to GDL) is safe for use in cosmetic formulations at concentrations typically used. It reviews available data on irritation and sensitization, supporting its safety for topical application.