Does Metformin Contain Any Ingredients Derived from Chicken?

Short answer: Standard metformin tablets and extended‑release tablets do not list any ingredients derived from chicken. Their inactive ingredients typically include starches (often corn/maize), cellulose derivatives, povidone, magnesium stearate, hypromellose (HPMC), polyethylene glycol, titanium dioxide, and similar excipients, none of which are chicken‑derived. ^{[1] [2] [3]}

That said, formulations can vary by manufacturer and product line, and a few metformin‑containing products or kits may include capsules made with gelatin, which is an animal‑derived excipient (commonly sourced from bovine or porcine collagen, not chicken). These are not typical plain metformin tablets but combined kits or special presentations. ^{[4] [5]}

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What’s in Standard Metformin Tablets?

Most metformin products are film‑coated tablets (immediate or extended release), not capsules. Their inactive ingredients commonly include:

• Corn starch or pregelatinized starch (maize)
• Povidone (polyvinylpyrrolidone), crospovidone
• Magnesium stearate
• Hypromellose (HPMC)
• Polyethylene glycol (PEG)
• Titanium dioxide
• Talc
• Microcrystalline cellulose
  These excipients are synthetic or plant/mineral‑derived and are not chicken‑derived. ^{[1] [2] [6]}

For example, extended‑release metformin tablets list corn starch, povidone, magnesium stearate, with coatings containing hypromellose, talc, titanium dioxide, polyethylene glycol, and propylene glycol. None of these are chicken ingredients. ^[1] Extended‑release formulations may also use sodium carboxymethyl cellulose, microcrystalline cellulose, and copovidone, which are likewise non‑animal and not chicken‑based. ^{[3] [7]}

Immediate‑release tablets similarly list pregelatinized starch (maize), povidone/crospovidone, magnesium stearate, and coatings with hypromellose, PEG, titanium dioxide, and flavoring agents; again, no chicken derivatives are indicated. ^[2] Additional versions list HPMC, maltodextrin, PEG, povidone, crospovidone, and stearic acid among excipients without any chicken source. ^{[8] [9]}

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Variability Between Manufacturers

Inactive ingredients can differ across brands and strengths, especially in extended‑release products that use more excipients to control drug release. For instance, some ER tablets include lactose monohydrate, ethylcellulose, oleic acid, medium‑chain triglycerides, xanthan gum, and silicified microcrystalline cellulose; while lactose is milk‑derived, none of these are chicken‑derived. ^{[10] [11] [12]}

Other metformin ER tablets may be “capsule‑shaped” but still tablets without gelatin shells, listing hypromellose, silicon dioxide, and magnesium stearate again not chicken‑derived. ^[13]

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When Might Animal‑Derived Excipients Appear?

While standard metformin tablets avoid gelatin, some metformin‑containing kits or combinations use gelatin capsules. Gelatin is animal‑derived (usually bovine or porcine), and although not from chicken, it is still an animal product that matters for dietary restrictions. Examples include metformin‑tyrosine kits listing gelatin among inactive ingredients. ^{[4] [14] [5] [15]}

Additionally, broader medication surveys show gelatin is common in many oral medications, potentially conflicting with dietary preferences, which underscores the importance of checking product‑specific labeling. ^[16]

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Practical Guidance

• If you are taking a standard metformin tablet (immediate or extended‑release) from common manufacturers, it does not contain chicken‑derived ingredients based on listed excipients. ^{[1] [2] [3]}
• If you are prescribed a metformin product that uses capsules or a combined kit, verify whether gelatin is present; it is animal‑derived (typically bovine or porcine), not chicken, but relevant for those avoiding animal products. ^{[4] [5]}
• Ingredient lists can change, so check the specific product label or ask your pharmacist to confirm the exact excipients for your brand and strength. ^{[1] [2] [10]}

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Summary

• Metformin tablets do not contain chicken‑derived ingredients according to published excipient lists for immediate‑release and extended‑release tablets. ^{[1] [2] [3]}
• Some specialized metformin products may include gelatin capsules (animal‑derived, typically bovine/porcine), but this is not chicken and is uncommon in standard tablet formulations. ^{[4] [5]}
• Always verify your exact product’s label, as inactive ingredients vary by manufacturer and presentation. ^{[10] [11] [8]}