iS Clinical Poly-Vitamin Serum

iS Clinical Poly-Vitamin Serum is an evening face serum built around 5% niacinamide, 40% sodium hyaluronate and a low 0.5% dose of retinol with a 4% botanical AHA (from sugarcane extract). It's positioned by iS Clinical as a gentler alternative for skin that can't tolerate daily active serums — not as an actives-free formula. Read on before assuming "niacinamide serum" means retinol- and AHA-free.

What it is

Poly-Vitamin Serum is a lightweight, fast-absorbing evening serum from iS Clinical, sold in 15ml and 30ml sizes. It's built around a multi-vitamin complex — niacinamide (B3), pantothenic acid (B5), retinol (A) and tocopherol (E) — alongside a high concentration of sodium hyaluronate for hydration and a botanical AHA for gentle exfoliation. It sits in iS Clinical's Targeted Serums group, next to Active Serum and Hydra-Cool Serum, and is designed as a once-daily evening step for dehydrated, stressed or ageing skin — or as a seasonal alternative for people who find daily active serums too much.

Despite the "poly-vitamin" name, it isn't an actives-free formula — the ingredient deck includes 0.5% retinol and 4% botanical AHA alongside the niacinamide and hyaluronic acid. iS Clinical frames it as a lower-strength, better-tolerated combination for people who can't manage daily retinoid use but still want some resurfacing benefit, rather than a formula built for those avoiding actives altogether. If you want a genuinely active-free evening hydrator, check the ingredient list below before you buy.

Key ingredients

This is a summary of the named actives from Shopify's published ingredient data, not the full INCI — check the product packaging for the complete list before you buy.

Who it suits — and who should be cautious

• Dehydrated, stressed or ageing skin that wants hydration plus mild resurfacing in one evening step
• Those who find daily retinol or AHA serums too strong but still want some active benefit, applied once a day
• Anyone using it as an occasional or seasonal alternative to a stronger active serum

iS Clinical is explicit that this isn't for everyone. It's not recommended for highly active rosacea, and the brand flags that some people experience temporary tingling or flushing on application, linked to the niacinamide and circulation-supporting ingredients — patch test first if you're prone to flushing or know you're niacin-sensitive. Because it contains retinol and AHA, it also carries the usual sun-sensitivity caution: use a broad-spectrum SPF 30+ by day while you're using it.

How to use it

iS Clinical directs Poly-Vitamin Serum for once-daily evening use on cleansed skin, followed by a moisturiser. Because of the retinol and AHA content, it's an evening-only step, and isn't designed to be layered with other retinol or strong-acid products the same night. If you're new to it, start a few nights a week rather than nightly, and watch for the tingling/flushing response the brand describes as normal before deciding whether it suits your skin.

Building it into a routine

Because Poly-Vitamin Serum sits between a hydrating serum and a mild active, it's usually chosen alongside — not instead of — the rest of an evening routine:

• Cleanse, then apply Poly-Vitamin Serum a few nights a week to start
• On other nights, or for hydration without retinol/AHA, reach for Hydra-Cool Serum instead
• If you're already comfortable with daily actives, compare it against Active Serum, iS Clinical's more established daily-active option
• Finish mornings with SPF 30 or higher while using this product

For more on what suits reactive or post-procedure skin, see our round-up of best iS Clinical products for sensitive and post-procedure skin.

Pregnancy and breastfeeding

If you're pregnant or breastfeeding, please contact our team for advice before use.

Our verdict

Poly-Vitamin Serum is a reasonable pick for hydration and mild resurfacing in a single evening step, if you can't manage a full daily-actives routine. It isn't an actives-free niacinamide serum, though: the 0.5% retinol and 4% AHA mean the same rosacea and sun-sensitivity cautions apply as with other mild retinoid products. Want zero active content? Hydra-Cool Serum is the better match; already comfortable with daily actives? Active Serum is the more established option.

FAQs

Is iS Clinical Poly-Vitamin Serum free from retinol and AHA?

No. Despite the "poly-vitamin" name, it contains 0.5% retinol and a 4% botanical AHA (from sugarcane extract) alongside 5% niacinamide and sodium hyaluronate. It's a lower-strength combination, not an actives-free formula.

Can I use it if I can't tolerate daily retinol?

iS Clinical positions it as a gentler alternative for people who find daily retinol or AHA serums too strong, used once daily in the evening rather than as a stronger nightly treatment. If you're highly retinoid-sensitive, it's worth checking with our team before starting.

Why does it cause tingling or flushing?

iS Clinical describes a temporary tingling or flushing sensation as a normal response linked to the niacinamide and circulation-supporting ingredients in the formula. If you have rosacea or know you're prone to flushing, patch test first, and it may not be suitable for highly active rosacea.

Do I need SPF while using this serum?

Yes. Because it contains retinol and AHA, it carries the usual sun-sensitivity caution — use a broad-spectrum SPF 30 or higher during the day while you're using it.

Is it safe to use during pregnancy or while breastfeeding?

If you're pregnant or breastfeeding, please contact our team for advice before use.

How does it compare to Hydra-Cool Serum?

Hydra-Cool Serum is a hydration-focused option without retinol or AHA, making it the better fit for anyone who wants to avoid actives altogether. Poly-Vitamin Serum adds mild resurfacing on top of hydration, for evenings when that's wanted.