Hyaluronic acid is one of the key components responsible for hydrated, supple skin and healthy joints. Today, it’s not only found in creams or injections, but also in dietary supplements, encapsulated for easy daily intake. But what do scientific studies say about the effects of oral hyaluronic acid? In this article, we take a look at the latest research findings.
Hyaluronic acid (HA) is one of the body’s fundamental components, playing a vital role in maintaining tissue hydration, elasticity, and mechanical stability. It is best known for its use in aesthetic skin rejuvenation treatments and intra-articular injections, yet in recent years, increasing attention has turned toward its oral, dietary supplement form.
The results of clinical trials available to date suggest that oral hyaluronic acid may contribute not only to alleviating joint discomfort but also to improving skin condition. Studies indicate that it enhances skin hydration, improves elasticity, and reduces the appearance of wrinkles. Particularly noteworthy are findings highlighting the efficacy of high molecular weight (HMW) hyaluronic acid, both in musculoskeletal health and skin rejuvenation. However, it is important to emphasize that the quality and quantity of existing evidence remain limited, and several questions—such as the long-term efficacy or the precise role of molecular weight—require further investigation.
Osteoarthritis, especially involving the knee joint, is one of the most common indications for hyaluronic acid therapy, particularly in injectable form. However, in recent years, interest in oral supplementation has also been growing.
In a randomized, double-blind, placebo-controlled pilot study, Jensen and colleagues administered a liquid preparation containing high molecular weight hyaluronic acid, which during the study period led to a significant reduction in pain and decreased use of analgesic medications [1].
In another randomized, 8-week study involving 60 patients, Cicero et al. administered a “full-spectrum” hyaluronate containing a high molecular weight (HMW) fraction, which produced short-term improvements in symptomatic scores of knee osteoarthritis [2].
Other studies have also reported symptom reduction following oral hyaluronic acid administration [3]; however, in several of these, data on molecular weight were lacking, making cross-study comparisons and unified conclusions difficult.
It is important to note that most of these trials were short-term and included relatively small sample sizes, which limits generalizability.
The cosmetic effects of oral hyaluronic acid have been evaluated in several randomized, controlled clinical trials. Kawada and colleagues (2014) demonstrated that both 300 kDa and 800 kDa sodium hyaluronate—administered at a daily dose of 120 mg for six weeks—improved skin hydration and reduced dryness. The effect was particularly pronounced in the higher molecular weight (800 kDa) fraction [4].
Other studies, such as those by Göllner et al. (2017) and Hsu et al. (2021), likewise reported significant improvements in skin hydration, elasticity, and wrinkle depth [5,6].
It should be added, however, that most studies were of short duration (6–12 weeks) and did not always specify the exact molecular weight, which limits the ability to assess the extent to which the observed effects depend on molecular weight variations.
Most clinical trials have used daily doses of 120–200 mg oral hyaluronic acid, typically for 4–12 weeks. Current evidence suggests that high molecular weight (HMW) forms are at least as effective as lower molecular weight variants and, in some cases, produced more pronounced improvements in skin hydration and elasticity.
In cases of joint complaints, symptomatic relief was generally observed in the medium term (after 8–12 weeks), whereas in skin studies, measurable changes were already reported after six weeks.
It is important to emphasize that, based on current data, no consensus has yet been reached regarding which molecular weight or formulation is most optimal in the long term.
Although the mechanism of action of oral hyaluronic acid is not yet fully understood, several animal and human studies suggest that orally administered hyaluronic acid is partially absorbed and may reach the joints in a biologically active form.
Kimura and colleagues (2016) demonstrated in an animal model that orally administered sodium hyaluronate is partially degraded into smaller molecular fragments, which can be absorbed from the large intestine and subsequently detected in the bloodstream [7].
Other studies indicate that these fragments may theoretically influence anti-inflammatory and matrix-regenerating processes, for example, by modulating the TLR-4 signaling pathway [8].
At the clinical level, several randomized controlled trials have demonstrated symptomatic improvement in knee joint discomfort.
Jensen et al. (2015), in a short, four-week, randomized, placebo-controlled pilot study, found that a liquid containing high molecular weight oral hyaluronic acid significantly reduced chronic pain and the need for pain medication [1].
Cicero et al. (2020) observed similar outcomes in an eight-week study using 200 mg/day of “full-spectrum” sodium hyaluronate, where WOMAC scores improved significantly [2].
A recent systematic review (de Carvalho et al., 2024) analyzing 11 clinical trials concluded that oral hyaluronic acid generally leads to improvements in pain and functional indicators, although data regarding direct chondroprotective effects remain insufficient [9].
Based on these findings, it can be hypothesized that oral hyaluronic acid contributes to improved joint comfort and mobility not through direct cartilage incorporation, but rather via systemic anti-inflammatory and cell signaling effects.
Clinical studies from recent years indicate that oral hyaluronic acid—particularly in high molecular weight form—may have beneficial effects on both skin and joint health. Regular intake may improve skin hydration, enhance elasticity, and help reduce the appearance of fine lines. In musculoskeletal complaints, multiple studies have demonstrated reductions in pain and improvements in quality of life.
However, it must be emphasized that:
Based on current evidence, a daily intake of approximately 120 mg high molecular weight hyaluronic acid may be considered a promising option both for cosmetic purposes and as an adjunctive therapy for joint discomfort. Nevertheless, accurate assessment of its long-term efficacy and safety requires further large-scale, well-designed clinical studies.
Oral hyaluronic acid is not a miracle cure, but current research suggests that it may indeed help increase skin hydration, reduce fine lines, and alleviate joint discomfort. Most studies demonstrated favorable short-term results, particularly with high molecular weight hyaluronic acid. However, long-term effects and optimal dosing still require confirmation through further research. For individuals seeking to support the health of their skin and joints, oral hyaluronic acid represents a promising complementary option, according to current scientific evidence.
| Indication | Author (Year) | Molecular Weight | Dosage | Duration | Findings | PMID |
|---|---|---|---|---|---|---|
| Joint pain (OA, chronic) | Jensen (2015) | HMW (high molecular weight, exact MW not specified) | Not specified (oral liquid solution) | 4 weeks | Pain reduction, decreased medication use | 25415767 |
| Knee OA | Cicero (2020) | Full-spectrum (includes HMW) | 200 mg/day | 8 weeks | Improved symptom scores | 32650511 |
| Knee OA | Sugiyama (2023) | Not specified | 111 mg/day | 12 weeks | Reduction in knee pain | 38234616 |
| Dry skin, hydration | Kawada (2014) | 300 kDa and 800 kDa (HMW) | 120 mg/day | 6 weeks | Improved skin hydration and elasticity | 25014997 |
| Skin aging, wrinkles | Hsu (2021) | HA 2K and HA 300k groups | 120 mg/day | 12 weeks | Reduced wrinkles, improved hydration and radiance | 34203487 |
The overview of studies presented above shows that the efficacy of oral hyaluronic acid is primarily supported by short- and medium-term clinical trials. Several key aspects can be highlighted:
Overall, the table illustrates that although the body of evidence is growing, research has yet to provide definitive answers regarding long-term efficacy and optimal application forms.
Based on the referenced studies, it is evident that the strongest methodological designs can be attributed to the trials by Jensen (2015) and Cicero (2020), both of which were double-blind and placebo-controlled, although each involved relatively small sample sizes. Sugiyama’s (2023) research is more recent but also limited in duration. Among the skin-related studies, Kawada (2014) stands out for its precise molecular weight characterization, while Hsu (2021) is notable for its longer 12-week follow-up period.
Overall, the cited sources are reliable and relevant, but the level of evidence is best classified as IIb–III (preliminary clinical trials) rather than large-scale, multicenter randomized studies. Therefore, based on current data, oral hyaluronic acid can be considered a promising adjunctive approach, though it has not yet reached the status of a standard therapy.
