Regarthro is a biologically active supplement which includes in 2 capsules

     • Glucosamine sulfate 2 NaCl – 1000 mg

     • Boswellia Serrata – Boswellic acid (65%) – 200 mg

     • Hydrolyzed Collagen II type – 80 mg

     • Sodium Hyaluronate – 60 mg

Glucosamine sulfate

Glucosamine in its acetylated form is a natural constituent of some glycosaminoglycans (for example, hyaluronic acid and keratan sulfate) in the proteoglycans found in articular cartilage, intervertebral disc and synovial fluid. Glucosamine can be extracted and stabilized by chemical modification and used as a drug or a nutraceutical. It has been approved for the treatment of osteoarthritis (OA) in Europe to promote cartilage and joint health and is sold over the counter as a dietary supplement in the United States. Various formulations of glucosamine have been tested, including glucosamine sulfate and glucosamine hydrochloride. In vitro and in vivo studies have uncovered glucosamine's mechanisms of action on articular tissues (cartilage, synovial membrane and subchondral bone) and justified its efficacy by demonstrating structure-modifying and anti-inflammatory effects at high concentrations. However, results from clinical trials have raised many concerns. Pharmacokinetic studies have shown that glucosamine is easily absorbed, but the current treatment doses (for example, 1,500 mg/day) barely reach the required therapeutic concentration in plasma and tissue. The symptomatic effect size of glucosamine varies greatly depending on the formulation used and the quality of clinical trials. Importantly, the effect size reduces when evidence is accumulated chronologically and evidence for the structure-modifying effects of glucosamine are sparse. Glucosamine is generally safe and although there are concerns about potential allergic and salt-related side effects of some formulations, no major adverse events have been reported so far. [1]

Boswellia Serrata

Boswellic acid is the active ingredient in Boswellia serrata; it has shown significant pharmacological activity in the treatment of inflammatory diseases such as rheumatoid arthritis, chronic bronchitis, asthma and chronic inflammatory bowel diseases (ulcerative colitis and Crohn’s disease) [2]. 
As potential anti-inflammatory drugs for OA, the efficacy of Boswellia and Boswellia Extract have been reported in a lot of clinical trials. Since 2003, many trials have explored the feasibility of Boswellia and its extracts for the treatment of Osteoarthrosis. In the meantime, the latest randomized controlled trials (RCTs) have assessed the benefits and adverse events of Boswellia and its extract for Osteoarthrosis. [3] 

Hydrolyzed Collagen II type

Collagen, an abundant extracellular matrix protein, has been found to have a lot of pharmaceuticals, medicine, food, and cosmetics applications. Increased knowledge of collagen sources, extraction techniques, structure, and properties in the last decades has helped develop more collagen-based products and tissue engineering biomaterials. Collagen products have been playing an important role in benefiting the health of the human body, especially for aging people. In this paper, the effects of collagen treatment in different clinical studies including skin regeneration, bone defects, sarcopenia, wound healing, dental therapy, gastroesophageal reflux, osteoarthritis, and rheumatoid arthritis have been reviewed. The collagen treatments were significant in these clinical studies. In addition, the associations between these diseases were discussed. The comorbidity of these diseases might be closely related to collagen deficiency, and collagen treatment might be a good choice when a patient has more than one of these diseases, including the coronavirus disease 2019 (COVID-19). It concludes that collagen-based medication is useful in treating comorbid diseases and preventing complications. [4] 
Hydrolyzed collagen in a form easily utilized by tissues to support flexible joints and youthful skin health. Hydrolyzed collagen has higher solubility compared to native collagen and the extraction of hydrolyzed collagen is simple. [5]

Sodium Hyaluronate

Intake of oral supplements with the aim of a cutaneous antiaging effect are increasingly common. Hyaluronic acid (HA) is a promising candidate, as it is the key factor for preserving tissue hydration. In this study, evaluated the effect of an oral HA preparation diluted in a cascade-fermented organic whole food concentrate supplemented with biotin, vitamin C, copper, and zinc on skin moisture content, elasticity, skin roughness, and wrinkle depths. [6]
Sodium hyaluronate is the sodium salt of hyaluronic acid, a glycosaminoglycan found in various connective tissue of humans. Sodium hyaluronate functions as a tissue lubricant and is thought to play an important role in modulating the interactions between adjacent tissues. It forms a viscoelastic solution in water. Mechanical protection for tissues (iris, retina) and cell layers (corneal, endothelium, and epithelium) are provided by the high viscosity of the solution. [7]

References
[1] Henrotin Y, Mobasheri A, Marty M. Is there any scientific evidence for the use of glucosamine in the management of human osteoarthritis? Arthritis Res Ther. 2012 Jan 30;14(1):201. doi: 10.1186/ar3657. PMID: 22293240; PMCID: PMC3392795.
[2] Singh GB, Atal CK. Pharmacology of an extract of salai guggal ex-Boswellia serrata, a new non-steroidal anti-inflammatory agent. Agents Actions. 1986;18:407–441. doi: 10.1007/BF01965005. 
[3] Yu G, Xiang W, Zhang T, Zeng L, Yang K, Li J. Effectiveness of Boswellia and Boswellia extract for osteoarthritis patients: a systematic review and meta-analysis. BMC Complement Med Ther. 2020 Jul 17;20(1):225. doi: 10.1186/s12906-020-02985-6. PMID: 32680575; PMCID: PMC7368679.
[4] León-López A, Morales-Peñaloza A, Martínez-Juárez VM, Vargas-Torres A, Zeugolis DI, Aguirre-Álvarez G. Hydrolyzed Collagen-Sources and Applications. Molecules. 2019 Nov 7;24(22):4031. doi: 10.3390/molecules24224031. PMID: 31703345; PMCID: PMC6891674.
[5] Wang H. A Review of the Effects of Collagen Treatment in Clinical Studies. Polymers (Basel). 2021 Nov 9;13(22):3868. doi: 10.3390/polym13223868. PMID: 34833168; PMCID: PMC8620403.
[6] Göllner I, Voss W, von Hehn U, Kammerer S. Ingestion of an Oral Hyaluronan Solution Improves Skin Hydration, Wrinkle Reduction, Elasticity, and Skin Roughness: Results of a Clinical Study. J Evid Based Complementary Altern Med. 2017 Oct;22(4):816-823. doi: 10.1177/2156587217743640. Epub 2017 Dec 4. PMID: 29228816; PMCID: PMC5871318.
[7] Boucher WS, Letourneau R, Huang M, Kempuraj D, Green M, Sant GR, Theoharides TC (January 2002). "Intravesical sodium hyaluronate inhibits the rat urinary mast cell mediator increase triggered by acute immobilization stress". The Journal of Urology.