blog-224458032341

Key summary: Rejuran Healer and skin hydration injections are both called skin boosters, but their ingredients and roles differ, and depending on skin condition they are sometimes combined. However, receiving both on the same day can make bumps more noticeable or longer lasting, so it is safer to divide the amount and depth by area, and to split the dates when skin condition or schedule does not allow both.

I hear the question of whether Rejuran and hydration injections can be done together all year round, but it increases noticeably when the seasons change. With skin feeling tight morning and evening, doing just one feels insufficient, while doing both brings worry.

The biggest worry is whether getting both at once will make the bumps rise more severely. Below, I explain how Rejuran and hydration injections differ, what to watch when combining them, and when to split the dates.

Both are skin boosters injected into the skin, so they easily feel like the same treatment. It is natural to think so since they share the same label, but they differ starting with the ingredient.

Rejuran injects PN, or polynucleotide derived from salmon, into the dermis. Rather than filling empty space, it works closer to supporting an environment in which tired skin recovers, so it is mainly considered when the skin has thinned, the texture has become rough, or fine lines stand out.

Hydration injections replenish moisture by placing hyaluronic acid in a shallow layer of the skin. Hyaluronic acid attracts water, so many people seek hydration injections expecting a moist, glowing look from a relatively early point.

Because the ingredients differ, the timing of noticeable change differs too. Hydration injections tend to bring a sense of moisture relatively early, while Rejuran tends to refine texture and elasticity gradually over several weeks.

The way results are maintained also differs slightly. Moisture added by hydration injections decreases gradually over time, so it is closer to periodic replenishment, while Rejuran is closer to building up the skin base through several sessions.

In short, hydration injections focus on filling the moisture you lack now, and Rejuran focuses on restoring the overall skin environment. It is less about which is better and more about which your skin needs more urgently. If inner tightness during seasonal change bothers you most, consider hydration injections first, and if thin, tired skin worries you more, consider Rejuran first.

Depending on skin condition, Rejuran and hydration injections are sometimes combined. Hydration injections address current dryness and Rejuran addresses the future skin environment, so their roles tend not to overlap, and people who want moisture and regeneration together often consider both during seasonal change.

The bumps you may worry about deserve attention here. Bumps are a reaction in which the injected area looks raised and uneven until the ingredient settles into the skin.

Both Rejuran and hydration injections are placed in relatively shallow layers at many points, so combining them on the same day can make bumps somewhat more noticeable or seem to last longer. Still, it cannot be said that combining them always worsens bumps, and in practice the difference depends greatly on the amount injected, the injection depth and the skin condition that day.

So when combining them, we first decide which of the two leads in each area and adjust so the amount does not concentrate in one spot. For example, cheeks where dryness gathers are centered on moisture, and areas with tired texture are centered on regeneration.

Thin-skinned areas such as around the eyes can show bumps more clearly even with the same amount, so we lower the amount and depth by one step. Most bumps subside over time, but if swelling or pain keeps getting worse, please inform the clinic without delay.

In the following situations, I do not give Rejuran and hydration injections on the same day: when the skin barrier is damaged and the skin is red and sensitive, when an important event is scheduled within a few days, and when it is your first skin booster and you do not yet know how your skin reacts.

In these cases, it is more comfortable and better for the result to receive one first, check the reaction, and move to the next after an interval. Whichever order you choose, avoiding saunas and alcohol for a few days and paying attention to moisturizing and sun protection makes recovery easier.

Before treatment, we measure the skin's moisture and texture in several ways, and after treatment we follow the bumps as they subside.

In the end, hydration injections deal with current moisture and Rejuran deals with the underlying skin environment. They can be combined, but they do not always have to be done together, and the order and method change according to what your skin needs most and how it is doing that day.

When do the raised bumps after the injection go down?

They are a reaction that occurs while the ingredient settles into the skin, so they often subside with time. However, if swelling or pain keeps worsening or you feel heat as well, we recommend contacting the clinic where you were treated right away.

My skin feels tight every change of season. Is cream not enough?

Cream acts mainly on the surface, while inner tightness tends to be more closely related to the moisture environment of deeper layers. It is best to check both barrier and moisture condition before deciding on a care direction such as Rejuran or hydration injections.

I have an important appointment next week. Can I get injections now?

Bumps, swelling or small bruises may appear for a few days after treatment, so if it is your first time, leaving some room in your schedule can be reassuring. Letting us know your upcoming schedule during the consultation helps in deciding the order.

O.N Clinic is located near Gangnam Station, so it is easy to reach by subway.

If you are considering combining Rejuran and hydration injections, it helps to note whether inner tightness or thinning skin bothers you most, whether you have had skin boosters before, and whether you have events coming up. This makes it easier to decide the order and method. If you have any questions, feel free to ask via Chat with us now.

Written by Dr. Oh Seung-min (Chief Director of O.N Clinic, graduate of Seoul National University College of Medicine, Academic Committee Chair of the Korean Society for Laser, Skin and Hair). His full background is available on the Medical Team page. First published 2026-10-29, last reviewed 2026-11-10

This article is for general information only. Suitable treatment and results may vary depending on each person's condition.