Hydrating injection (water-light injection), does moisture really increase? What research has revealed and what remains unclear

Hydrating injection (a treatment that injects hyaluronic acid finely into shallow layers of the skin) has been reported in compiled research to increase skin moisture content and luster[1]. On the other hand, skin elasticity and the color of age spots show no clear difference[1]. Most research studies involve small sample sizes, and confirmation through large-scale trials is still being pursued[2].

Does hydrating injection increase skin moisture?

Reports primarily indicate increased moisture. A compiled report examining 12 studies, with data from 6 of them, showed that after injection, skin moisture content and luster increased[1].

A review of 13 studies examining hyaluronic acid injection also showed improvement in moisture, elasticity, skin texture, and luster[2]. It is also noted that hyaluronic acid alone showed clearer effects compared to injections mixed with other ingredients[2].

How effective is it for elasticity and fine lines?

Results for elasticity vary depending on the study. A compiled report with pooled data showed no clear difference in elasticity[1]. A separate review of studies showed that elasticity also improved[2].

In studies comparing hyaluronic acid injected on one side of the face with saline on the other, some found no difference in wrinkles or satisfaction[1]. Skin elasticity is thought to be more influenced by deeper collagen and other fibers than by hyaluronic acid[1].

Hydrating injection is not a treatment for deep wrinkles or changing facial contours. It is a treatment aimed at gradually improving skin texture and color evenness to enhance skin quality[3].

How long does the effect last? How many sessions are needed?

One guideline suggests 3 sessions at approximately one-month intervals[4]. It is recommended to continue at intervals of roughly once per month for multiple sessions, with the number varying based on concerns and goals[2].

A compiled report on injections to the neck and similar areas states that effects last 6 to 8 months[4]. However, there are still few long-term follow-up studies, so please consider this as a rough guideline.

In a study of 24 people receiving 3 injections at 3-week intervals, skin moisture values increased from 23.1 to 33.2[5]. This is a small study without a comparison group, so the authors themselves note that confirmation through a larger trial is necessary[5].

What side effects are there?

The most common are redness, swelling, and small bumps at the injection site. In compiled research reports, most of these resolved within about 3 days[1].

Because multiple sites are injected with a needle, bruising and swelling may persist for several days[6]. Reports on injections to the neck and similar areas note that swelling occurred in about 1 in 4 people, and bruising and similar effects resolved in 7 to 10 days[4].

Rarely, there have been reports of nodules (granulomas) or infections from bacteria or fungi[4]. If nodules or redness persist, consult the clinic where you had the procedure as soon as possible.

In treatments involving injection of hyaluronic acid into facial wrinkles, there have been reports of skin necrosis (tissue damage and darkening) or blindness when the injection enters blood vessels, and caution is advised[7].

Which concerns is hydrating injection suited for, and which is it not suited for?

When the research results are organized by concern, they are as follows:

Well-suited: skin dryness, lack of luster, rough skin texture[1][2]

Results vary: skin elasticity (firmness)[1][2]

No clear difference: age spot color[1]

Different goal: deep wrinkles, change in facial contours[3]

What should you confirm before having the procedure?

During consultation, ask about the following points:

Contents: hyaluronic acid alone or mixed with other ingredients[2]

Number of sessions: how many sessions and at what intervals[2][4]

Downtime: how long swelling and bruising are likely to persist[4][6]

Complications: how to address nodules or infection if they occur[4]

How effective it will be for your skin cannot be determined by this article alone. During your consultation, have your skin examined to identify whether your concern is dryness or texture versus deep wrinkles or sagging, and confirm which treatment is right for you.