Choosing a product: - Look for third‑party testing (USP, NS…

Choosing a product:
- Look for third‑party testing (USP, NSF, Informed Choice). Standard ascorbic acid works well; “buffered” forms (e.g., calcium/sodium ascorbate) can be gentler on the stomach. Sustained‑release can improve tolerance. “Liposomal” forms have limited human evidence.