Bufei Yishen Granules (BYG)

What It Is

• Bufei Yishen Granules (BYG) is a Chinese herbal formulation (in granule / decoction form) designed under Traditional Chinese Medicine (TCM) theory. Some sources refer to it as “Bufei Yishen formula” or “BYF / BYF formula.”
• The name “Bufei Yishen” literally suggests “tonify the lung, augment the kidney” (in TCM parlance, “Bu” = tonify, “Fei” = lung, “Yi Shen” = benefit / support kidney). It is typically used in patients classified under certain TCM “syndromes” (e.g. lung–kidney qi deficiency).
• Clinically, BYG has been studied particularly in patients with moderate to severe COPD (e.g. GOLD stage 3–4) and in people who tend to experience frequent exacerbations. Dove Medical Press
• The formulation is often combined with standard Western medical treatments (e.g. inhalers, supportive care) as a complementary therapy, rather than a standalone replacement. sup.jclinque.com

How It Works

Because BYG is a multi-herb formula, its action is likely multi-mechanistic. Research (both preclinical and clinical) has investigated several pathways and effects; here is a synthesis:

Anti-inflammatory modulation

• COPD is associated with chronic inflammation in the airways, and acute exacerbations often involve surges in pro-inflammatory cytokines. Animal studies show that BYG (or related formulae) can reduce levels of inflammatory biomarkers (e.g. IL-6, IL-1β, TNF-α, CRP) and reduce infiltration of inflammatory cells. cmrd.hactcm.edu.cn
• In rat models of COPD or exacerbation risk window, treatment with BYG reduced systemic inflammation and improved recovery speed.

Immune regulation, especially T cell balance (Th17 / Treg)

• One mechanistic study found that BYG helps restore the balance between T helper 17 (Th17) cells and regulatory T (Treg) cells, suppressing Th17 differentiation and promoting Treg differentiation, which is favorable for reducing harmful immune overactivation. Frontiers
• The effect may involve adenosine A2a receptor pathways, among others. Frontiers

Antioxidant / anti-oxidative stress effects

• Some of the constituent herbs likely contain flavonoids, polyphenols (e.g. quercetin, kaempferol) that can scavenge reactive oxygen species. A systems pharmaco-network analysis highlighted quercetin, kaempferol, and β-sitosterol among key compounds acting on multiple targets. acuatlanta.com

Tissue protection, attenuating structural/functional damage

• In animal models, BYG has been shown to reduce histopathologic damage to lung tissues (less alveolar destruction, less airway remodeling) compared to untreated COPD models. Wiley Online Library
• It may also enhance repair or reduce further damage by modulating signaling pathways (e.g. NF-κB, TGF-β / Smad signaling) involved in inflammation and fibrosis. cmrd.hactcm.edu.cn

Symptom relief and functional improvement

• Through the above effects (less inflammation, improved tissue status, immune balance), BYG may reduce symptoms like dyspnea, cough, and sputum production, and improve exercise tolerance (e.g. longer 6-minute walk distances) in patients. Dove Medical Press

Component optimization / “effective-constituent compatibility”

• Some researchers have attempted to isolate the “active core” or effective‐constituent subsets of the formula (ECC-BYF) to simplify and standardize dosing while maintaining efficacy. One study showed that ECC-BYF had comparable anti-inflammatory effects to the full BYF formula. ScienceDirect

Thus, BYG is considered to act synergistically via multiple pathways relevant to COPD pathology: dampening inflammation, regulating immune responses, protecting lung structure, and improving symptoms.

Why It’s Important

From both the TCM and biomedical perspectives, BYG holds significance in several areas:

Reducing acute exacerbations in COPD

• In a randomized, double-blind, placebo-controlled trial of 348 patients with GOLD stage 3–4 COPD, BYG use (administered twice daily, 5 days on / 2 days off) for 52 weeks significantly reduced the frequency of acute exacerbations (AEs) and AE-related hospitalizations compared to placebo. Dove Medical Press
• The mean reduction in AE frequency was about 0.35 events per year (95% CI: −0.61 to −0.10). Dove Medical Press
• In that trial, secondary outcomes such as 6-minute walk distance (improvement of ~40.9 m), dyspnea scores, symptom scores, and quality of life scores also improved significantly.
• However, no statistically significant effect was found on mortality or pulmonary function indices (e.g. FEV₁) in that trial.

Symptom control and quality of life

• For many patients with COPD, reducing the burden of symptoms, improving daily exercise capacity and quality-of-life metrics (shortness of breath, fatigue, etc.) is just as clinically meaningful as changing lung function metrics. The benefit of BYG in these domains may make it a valuable adjunct therapy. Wiley Online Library

Complement to standard therapy

• Because conventional COPD therapies (e.g. bronchodilators, corticosteroids, etc.) have limitations (side effects, incomplete control of exacerbations), BYG offers a potential complementary approach that may reduce exacerbations without overlapping major toxicities. Frontiers
• On economic grounds, one protocol describes planning a health economics evaluation to see if BYG is cost-effective vs placebo in reducing exacerbations and hospitalizations.

Bridging traditional and evidence-based medicine

• BYG is an example of how TCM formulations are being studied in controlled trials, combining traditional theory (e.g. lung-kidney qi deficiency) with modern pharmacology, immunology, and clinical endpoints. Its ongoing trials help move TCM therapies into a more evidence-aligned framework. Frontiers

So, BYG is important because it may offer a complementary tool to reduce exacerbations, improve symptoms, and potentially reduce healthcare utilization in COPD — areas where existing therapies still have gaps.

Considerations, Limitations & Risks

While BYG shows promise, there are several important caveats, constraints, and safety considerations. These should temper overinterpretation and guide prudent use or further research.

Quality & consistency of evidence

• Although there is at least one randomized, double-blind, placebo-controlled trial showing benefit, the magnitude of effect is modest, and the population studied is limited (e.g. mostly Chinese patients with severe COPD) Dove Medical Press
• The trial did not show significant changes in mortality or lung function (e.g. FEV₁) over placebo, which raises questions about whether BYG modifies disease progression or mainly provides symptomatic/exacerbation control. Dove Medical Press
• The generalizability to other populations (non-Chinese, different ethnicities, different concomitant therapies) is uncertain.
• Some published reviews and meta-analyses of “Bufei / Bufei Yishen / related formulas” note heterogeneity among studies, variable methodological quality, and possible publication bias. Wiley Online Library
• Some trials are still ongoing (e.g. NCT06326658) to further evaluate efficacy, safety, and health economic impacts over longer durations and in larger samples. Frontiers

Mechanistic uncertainties

• Because BYG is a multi-component herbal mixture, attributing effects to individual herbs or compounds is difficult. The interactions (synergy, antagonism) among components are complex.
• Many mechanistic studies are in animal or ex vivo models, which may not directly translate to human disease.
• The precise molecular targets of many constituent compounds remain incompletely characterized.

Herb–drug interactions and safety

• As with any herbal therapy, there is the potential for interactions with standard medications (e.g. bronchodilators, inhaled corticosteroids, systemic drugs). These interactions are not yet thoroughly mapped.
• The safety profile in the clinical trial was acceptable (no obvious adverse events) in the patient population studied. Dove Medical Press
• But ‘absence of obvious adverse events’ over a 1-year trial does not rule out rare toxicity, long-term safety issues, or idiosyncratic reactions (e.g. liver or kidney issues, allergies, interactions) in broader use.
• Because herbal medicines sometimes include bioactive compounds affecting liver enzymes or renal clearance, one must monitor liver and kidney function, especially in patients with comorbidities.

Standardization, quality control, and formulation variability

• Herbal products often suffer from batch-to-batch variability in active compound concentrations, depending on source, processing, storage, and formulation.
• Without rigorous standardization, the actual dose of active compounds may differ between preparations, potentially affecting efficacy and safety.
• Some investigators are working to define “effective-constituent compatibility” (ECC) to reduce complexity and improve reproducibility. ScienceDirect

Patient selection and TCM syndrome differentiation

• In TCM practice, prescriptions like BYG are often tailored to underlying “syndrome differentiation” (e.g. lung-kidney qi deficiency). Its benefit may depend on appropriate patient matching.
• In trials, inclusion criteria often require that patients meet those TCM syndrome types, which may limit applicability to all COPD patients. For example, one trial requires that patients’ TCM diagnosis corresponds to qi deficiency of lung and kidney, or related syndromes. ctv.veeva.com

Regulation, availability, and cost

• In many countries, herbal preparations like BYG may not be regulated or approved in the same way as pharmaceutical drugs. Quality, labeling, and oversight may vary.
• The cost-effectiveness needs to be demonstrated; whether the cost of BYG plus conventional therapy is justified by reductions in hospitalizations/exacerbations is under investigation (some protocols plan economic analyses). Frontiers

Not a substitute for standard therapy

• BYG should not displace evidence-based standard COPD treatments (e.g. inhaled bronchodilators, pulmonary rehabilitation, vaccinations, etc.). It is best viewed as a complementary therapy.
• Overreliance on BYG without adequate management of comorbidities, infections, or acute exacerbations could be dangerous.