Hyaluronic acid (oral)

SkinJointsEyes

The molecule that fills the spaces between your cells with water. Used orally for skin hydration, joints, and dry eye — with surprisingly good evidence.

EvidenceModerate

Moderate for skin hydration, fine line / wrinkle improvement, and knee osteoarthritis pain. Smaller evidence base for dry eye improvement. Effects: 4–12 weeks.

Hyaluronic acid is a glycosaminoglycan that holds up to 1,000 times its weight in water. It's the main component of synovial fluid (joint lubricant), vitreous humour (eye), and the extracellular matrix that holds skin tissue together. Oral hyaluronic acid was once dismissed (the molecule is large and seems too big to absorb), but multiple studies now show that low-molecular-weight HA does reach circulation, accumulate in skin and joints, and produce measurable benefits. Best evidence is in skin hydration / wrinkle improvement and in knee osteoarthritis pain. Topical and injectable HA have their own established uses.

Form
Low-molecular-weight (LMW) hyaluronic acid — better absorbed. Brands: Mobilee, Injuv. Standard hyaluronic acid works too but with lower bioavailability.
Dose
120–240 mg/day. Skin / joint trials use 120–200 mg.
Timing
Anytime, with or without food.
Schedule
Daily.
Side effects
Generally very well-tolerated. Mild GI upset rare.
Interactions
Generally clean. Theoretical: anticoagulants (no significant data).
Contraindications
Allergy to source (some HA is fermentation-derived, some animal). Active cancer (theoretical — HA is involved in cellular signalling).
Lab markers
Not standard. Skin elasticity / hydration testing, joint function.
Food sources
Bone broth (long-simmered with connective tissue and joints), chicken skin, beef tendons. Trace amounts in some fermented foods.

Pairs with

Collagen peptides + vitamin C (skin and joint stack). Glucosamine + chondroitin (joint stack). Astaxanthin (skin synergy).