Rejuran: Hand Injection vs. Machine Injection — What's the Difference?

Whether to choose hand injection or machine injection for Rejuran depends on whether you value precision of results more or comfort during the procedure more. Dr.Evers Clinic · Busan Seomyeon lays out the differences between the two methods in technique, precision, pain, and post-treatment bumps, so you can compare them against your own situation.

How are hand injection and machine injection each done?

With hand injection, the doctor holds the needle and manually injects point by point across the face into the dermis; with machine injection, a negative-pressure device such as a water-drop gun or a nine-needle device suctions the skin and then uses multiple needles to quickly inject the product evenly.

• Hand injection is performed point by point by the doctor, so injection depth and dose can be adjusted at any time
• Machine injection relies on the device's suction to hold the skin, with multiple needles entering at once, spreading the points evenly across the face

What are the pros and cons of each method?

Hand injection wins on precision and low waste; machine injection wins on low pain and speed, at the cost of a slight amount of leakage.

With hand injection, the product leakage rate is low, and every drop of Rejuran is precisely delivered into the dermis; in areas with thin or delicate skin such as around the eyes, the tear troughs, and the sides of the nose, the doctor can adjust depth and dose at any time. However, the needle sensation is stronger, so good anesthesia and pain tolerance are needed, and the small bumps on the face after treatment may last 1–3 days — this is a normal sign of the product remaining in the dermis.

During machine injection, the device's suction helps distract from the pain, the treatment is fast, and the experience is more comfortable, with redness and bumps subsiding more quickly. But because of the device's negative-pressure suction and the angle at which the needles withdraw, a small amount of product will more or less leak out through the epidermis.

How should someone who fears pain or bumps choose?

If you are very afraid of pain, bruising, and bumps, machine injection can offer a more comfortable experience while still achieving excellent deep hydration and repair results.

If you want to make the most of Rejuran's repair benefits, especially when treating the eye area with the white box or the whole face with the black box, hand injection is the method more valued for its results. The two methods are not an either-or choice; how to arrange things in practice depends on how much importance you personally place on precision and on comfort.