Use the label to confirm you’re getting measurable actives, not vague blends. For omega-3s, look for stated amounts of EPA and DHA (not just “fish oil mg”), because EPA/DHA are the meaningful fatty acids. Products should disclose EPA/DHA per serving and provide clear feeding directions by weight.
For biotin, more isn’t automatically better. Many formulas include it, but extremely high doses can be unnecessary; look for a stated biotin amount (not hidden in a “proprietary blend”) and treat it as supportive rather than a standalone solution.
For zinc, prefer clearly identified, bioavailable forms (e.g., zinc methionine/chelated forms) with an explicit dose. Avoid stacking multiple high-zinc products unless your vet directs it.
Amino acids and protein-support ingredients can be useful, but prioritize transparency: exact amounts, not marketing names. Finally, quality markers matter for oils: oxidation control (dark bottles, antioxidants like mixed tocopherols, clear “best by” dates, and storage guidance) and third-party testing/COAs for purity and potency. If a brand won’t discuss oxidation management or provide third-party testing, it’s reasonable to pass.