Bestatin (Ubenimex) vs Thymosin Alpha-1 — Peptide Comparison

Bestatin (Ubenimex) vs Thymosin Alpha-1 — Peptide Comparison Bestatin (Ubenimex) vs Thymosin Alpha-1 — compare dosing, benefits, safety profiles, side effects, and how they stack. See which peptide is right for you. At a Glance Dose Range Bestatin (Ubenimex) 10–100 mg Thymosin Alpha-1 1.6–3.2 mg Frequency Once daily Twice weekly Administration Oral (capsule) Subcutaneous injection Cycle Length 12+ weeks 8-12 weeks Onset Speed Moderate (1-2 weeks) Evidence Level Moderate human trials (Phase 1-2) Efficacy Immune Healing & Recovery Anti-Aging Immune Activation Infection Fighting Immune Balance Technical Data Molecular Formula C16H24N2O4 Molecular Weight 308.37 g/mol Half-Life Approximately 2-3 hours (oral administration) Bioavailability Well absorbed orally; peak plasma concentration reached within 1-2 hours CAS Number 58970-76-6 C129H215N33O55 3108.32 g/mol Approximately 2 hours High when injected subcutaneously (rapid absorption, peak at ~2 hours) 62304-98-7 Protocols standard 30 mg Long-term, alongside maintenance chemotherapy 30 mg by mouth once daily is the approved Japanese dose used as add-on therapy after leukemia remission. It helped patients, especially older adults, stay in remission longer [4][1]. 1.6 mg Twice weekly (3-4 days apart) 6-12 months Established clinical dose for thymalfasin (Zadaxin); body-surface-scaled as 900 mcg/m2 [4][6]. Phase III chronic hepatitis B trials used 1.6 mg SC twice weekly for 6-12 months [4]. advanced 1.6 mg daily, then 1.6 mg twice weekly Daily for an initial loading period, then twice weekly Some immune-adjuvant and acute protocols front-load with daily dosing before settling to the standard twice-weekly schedule [4][6]. Applications Adjunctive AML Immunotherapy Bestatin is specifically approved in Japan for patients with acute non-lymphocytic leukemia who have achieved complete remission after induction chemotherapy. Clinical trials demonstrated significant prolongation of disease-free survival when bestatin was added to standard maintenance therapy. Post-Chemotherapy Immune Recovery By stimulating bone marrow stem cell proliferation and enhancing T-lymphocyte and macrophage function, bestatin supports immune system recovery in patients whose immune function has been suppressed by cytotoxic chemotherapy. Pulmonary Arterial Hypertension (Investigational) Through inhibition of LTA4 hydrolase and reduction of pro-inflammatory leukotriene B4, bestatin is being investigated as a novel approach to PAH. Eiger BioPharmaceuticals conducted Phase 2 trials (NCT02664558) and received FDA orphan drug designation for this indication. Lymphedema Management (Investigational) The anti-inflammatory properties of bestatin via LTB4 pathway inhibition have led to Phase 2 investigation (NCT02700529) for lymphedema, a condition with limited treatment options where inflammation plays a key role in disease progression. Chronic Hepatitis B or C Support Thymosin Alpha-1 has its strongest clinical evidence here. Multiple trials show it helps clear viral loads and normalize liver enzymes, especially when combined with antiviral medications. It's approved in over 30 countries specifically for hepatitis treatment. Cancer Treatment Support When used alongside chemotherapy, Thymosin Alpha-1 may help maintain immune function that chemo tends to suppress. Research in lung cancer, melanoma, and liver cancer shows improved outcomes when added to standard treatments. It helps your immune system keep fighting even during tough treatments. Age-Related Immune Decline As you age, your thymus shrinks and produces less thymosin naturally—a process called immunosenescence. Supplementing with Thymosin Alpha-1 may help compensate, keeping your immune defenses more youthful and responsive. Think of it as replacing what your body makes less of over time. Severe Infection Recovery In sepsis and critical infections, Thymosin Alpha-1 has shown promise for reducing mortality by helping restore immune balance. It's particularly interesting because it modulates immunity rather than just boosting it—calming overreaction while enhancing pathogen-fighting ability. Safety Profile Common Gastrointestinal discomfort Skin rash or pruritus Facial flushing Fatigue Uncommon Elevated liver enzymes Mild leukopenia Serious Severe allergic reaction Injection site reactions Mild fatigue Flu-like symptoms Mild fever Lymph node awareness Allergic reaction Research Status FDA Status Research compound Safety Overview Bestatin (ubenimex) has an established safety profile based on decades of clinical use in Japan for AML maintenance therapy at 30 mg daily. The compound is generally well-tolerated, with the most common side effects being mild gastrointestinal symptoms and skin reactions. Japanese post-marketing surveillance and long-term clinical studies have not identified major safety concerns at standard doses. Phase 2 trials in the US for PAH and lymphedema also demonstrated acceptable safety profiles at higher doses. Contraindications xKnown hypersensitivity to bestatin or any component of the formulation xPregnancy and breastfeeding (insufficient safety data) xSevere hepatic impairment xActive autoimmune diseases in flare FDA approved for other use Thymosin Alpha-1 has one of the most extensive safety records of any peptide, with decades of clinical use across multiple countries. Studies consistently report minimal side effects—mostly limited to mild injection site reactions. The 2-hour half-life means it doesn't accumulate in your system. It's been used safely in thousands of patients with hepatitis, cancer, and other serious conditions. xOrgan transplant recipients on immunosuppressants xActive autoimmune disease flares xKnown allergy to thymosin peptides xPregnancy or breastfeeding xChildren under 18 without medical supervision Decision Guide Choose Bestatin (Ubenimex) if... Adjunctive immunotherapy following chemotherapy for acute leukemia Restoring immune function during and after cancer treatment Supporting bone marrow recovery post-chemotherapy Emerging treatment for pulmonary arterial hypertension (PAH) Choose Thymosin Alpha-1 if... Immune system strengthening Chronic infection support Cancer adjunct therapy Healthy aging immune support