😩 “How often should this ‘black box’ treatment be administered?” —— Getting the interval between treatments wrong directly reduces the effectiveness of the treatment.
I’ve seen so many people asking this question online: How often should Rejuran PN be used? Some say once a month, others say every three months, while yet others believe that using it once every six months is sufficient. Which one is correct? 🤷♀️
When I got my first black box treatment, I didn’t understand what was happening either. I just left right after the injection. Three months later, when I went for a follow-up visit, the doctor said, “You should have come back for the second injection one month later…” As a result, the effectiveness of the treatment was reduced by half. If you are also wondering how to determine the interval between treatments, this article will help you figure it out once and for all.
Let me state the conclusion first: The standard treatment regimen for Rejuran PN consists of 3 sessions per cycle, with each session spaced 3 to 4 weeks apart. Subsequently, maintenance treatments should be carried out every 6 to 12 months. However, the specific frequency should be adjusted according to your skin type, age, and budget. You can add WeChat friend s-sourire to have a professional consultant help you determine the most suitable treatment schedule.
🔬 The recovery period of Rejuran PN: Why must the interval be neither too short nor too long?
The main component of the black box is PN (Polynucleotide). Its function is to activate the self-repair mechanism in the dermis, thereby stimulating the production of new Collagen. This process follows a specific temporal rhythm:
- 🧬 Days 0–7: PN is released into the dermis, triggering an inflammatory repair response (mild redness is normal).
- 🧬 Days 7–14: Fibroblasts become active, and the synthesis of Collagen accelerates.
- 🧬 Days 14–28: The newly produced Collagen gradually matures, and the texture of the skin begins to improve.
- 🧬 Days 28–42: The level of Collagen remains relatively stable, and the effects enter a plateau phase.
This is exactly why a 3-4-week interval is considered the optimal time frame: before the effects of the first dose of collagen regeneration have stabilized, the second dose can be administered to enhance these reparative effects. If the interval is too short (within 2 weeks), the skin has not yet fully recovered, and administering another dose may increase the risk of side effects. On the other hand, if the interval is too long (more than 8 weeks), the effects of the first dose will have already stabilized, and administering a second dose would essentially mean starting the process over again, losing the synergistic benefit of the combined treatments.
📋 Recommended treatment interval charts for different skin types
| Skin type | Recommended interval | Number of treatments per session | Maintain the frequency |
|---|---|---|---|
| Young people aged 20-30 who are showing early signs of aging | 4 weeks | Three times | Once or twice a year |
| Mid-life aging between the ages of 30 and 40 | 3 to 4 weeks | 3 to 5 times | Once every six months |
| Severe sagging in individuals over 40 years of age | 3 weeks | 5 to 6 times | Once every 4 to 6 months |
| Sensitive skin/rose acne | 4 to 6 weeks | Three times | Once a year |
💰 Cost reference: In South Korea, the cost of a single session in a Dermatology clinic ranges from ₩300,000 to ₩500,000 (approximately NT$6,700 to NT$11,200). A complete treatment course, consisting of 3 sessions, usually costs around ₩900,000 to ₩1,500,000. Some clinics offer package discounts, which are typically 10–15% cheaper than individual sessions.
🏥 Which is the best option for anti-aging treatments in South Korea? A comparative review of Cheongdam beauty pleasure and JinYang JiShi
I have undergone black box procedures at two clinics in South Korea, and the experience was quite different in both cases.
Cheongdam Beauty Pleasure Dermatology – The premium option for an ultimate experi
ence
📍 Just 8 minutes’ walk from Apgujeong Station | Prices: ₩400,000–₩500,000 per treatment
The doctor’s manual injection technique is very precise, leaving
almost no bruising after the procedure. The waiting area is equipped with snacks and charging cables, and a translator is available throughout the visit. The downside is the relatively high cost, and appointments are difficult to secure; it is recommended to book at least 2 weeks in advance. Adding WeChat friend s-sourire can help with making the reservation, saving you the hassle of calling manually.
Kim Yang-ji Dermatology – A established specialty clinic with a high cost
-performance ratio
📍 Just a 5-minute walk from Sinsa Station | Prices: ⩺330,000–380,000 KRW per treatment
Kim Yang-ji is a well-established clinic
in Nonhyeon-dong, and its doctors have extensive experience. The injections are administered quickly but may be a bit more aggressive; I developed two small bruises after the treatment, which disappeared within 5 days. However, the prices are 20–30% lower than those at beauty pleasure in Cheongdam. If your budget is limited, Kim Yang-ji is a great option.
📅 Recommendations for scheduling Rejuran PN treatments: Coordinate them with your travel plans to South Korea.
Most Taiwanese who go to South Korea for cosmetic procedures do so as part of short-term trips, so planning the schedule is very important. Here are some arrangements I recommend:
Option A: One-time experience (3–5-day itinerary)
Get the treatment just onc
e to experience the results, and then return to Taiwan for follow-up treatments at local medical beauty clinic
s.
Suitable for: First-time users with limited budgets.
Option B: Two consecutive treatments (7–10-day stay)
Day 1: Fi
rst injection → Day 28–30: Second injection (this means staying in South Korea for a month or making two trips).
Suitable for: Those with e
xtended holidays or who are willing to make two flights.
Option C: Complete treatment course (3 sessions, with an interval of 3–4 weeks between each session)
This i
s the most effective option, but it requires 3 flights to South Korea or a stay of 2–3 months there.
Suitable for: Those who plan to reside in Sout
h Korea for an extended period, international students, and business travelers.
💡 Cost-saving tips: Many Dermatology clinics in South Korea offer discount “package deals” – paying for three treatments at once saves 10–20% compared to paying for them individually. However, it’s important to note that these packages usually have an expiration date (6 months or 1 year), after which they become invalid. Therefore, if you don’t travel to South Korea frequently, it might be safer to pay for each treatment separately.
⚠️ Common misconceptions regarding the interval between black-box treatments
❌ Misconception 1: The more frequently you treat it, the better the r
esults.
Wrong! The skin needs time to heal and produce Collagen. Treating it once every two weeks will actually keep the skin in an inflamed state, resulting in poor outcomes and increasing the risk of complications.
❌ Misconception 2: One treatment is enough to last for half a year.
The effects of a single treatment generally last for about 4–6 weeks at their peak, after which they gradually diminish. It takes three complete treatment sessions to achieve a duration of 6–12 months.
❌ Misconception 3: Just like hyaluronic acid injections, black box treatments can be done every month.
That
’s not right! Hyaluronic acid injections are superficial treatments that allow for quick recovery, so they can be performed monthly. However, black box treatments involve deep PN injections that stimulate collagen regeneration and therefore require a minimum interval of 3 weeks between sessions.
📱 Don’t know how to plan your treatment schedule? Add WeChat at s-sourire for one-on-one consultation. Just tell them about your schedule and budget, and they will help you find the most suitable planning option.
Combination options of Rejuran PN with other hyaluronic acid injections in 🇰🇷
Many Dermatology departments in South Korea recommend using the black box in combination with other hyaluronic acid injections for better results. Here are some common combinations:
- 💧 Black box treatment + basic hyaluronic acid injection: The most classic combination. Hyaluronic acid injection provides hydration, while the black box treatment helps with repair – 1+1 > 2. It is recommended to undergo the black box treatment first, followed by the hyaluronic acid injection.
- 💧 Black box treatment combined with vitamin C hyaluronic acid injection: Suitable for dull skin. The black box repair technology combined with vitamin C helps to brighten the skin, making it look much more radiant after the treatment.
- 💧 Black box treatment + Botulinum toxin: Designed for enlarged Pores and excessive sebum production. Botulinum toxin helps control sebum, while the black box treatment helps tighten the Pores – together, these treatments achieve double the effect.
- 💧 Black box + Juvelook: Suitable for those with Tear trough correction and poor skin quality. Juvelook fills in the Tear trough correction areas, while the black box helps improve skin quality. However, this combination is relatively expensive, so ensure you have sufficient budget.
⚠️ Note: The more treatments you undergo on the same day, the longer your face will remain swollen (possibly for 3 to 5 days). If you are on a short vacation, it is recommended to schedule these treatments separately. It is generally not a problem to have hyaluronic acid injections and “black box” treatments on the same day, but adding botulinum toxin injections will cause more noticeable swelling.
❓ FAQ on Common Issues Regarding the Intervals Between Rejuran PN Treatments
Q: Can the black box treatment and HB (black box treatment + hyaluronic acid injection) be done on the same day?
A: Yes. Man
y clinics in South Korea recommend performing both the black box treatment and hyaluronic acid injection at the same time. The hyaluronic acid injection provides superficial hydration, while the black box treatment helps with deep-level repair, resulting in enhanced effects. However, the amount of fluid injected in a single session is relatively large, and the swelling on the face may last for 3 to 5 days.
Q: What should I do if I miss a dose in the middle?
A: If the
interval between doses exceeds 8 weeks, it is recommended to start counting the treatment cycle over again. If you only miss one week (so you have received 5 doses in total), the impact is minimal; you can simply continue with the treatment as usual. However, do not try to shorten the interval between doses in order to “catch up” on the missed dose.
Q: How long should one wait after undergoing a black box treatment before proceed
ing with other treatments?
A: A minimum interval of 2 weeks is recommended. If you plan to combine it with treatments such as Thermage or Pico, it is advised to perform instrument-based treatments first, followed by injectable treatments, with an interval of 2–4 weeks between them.
Disclaimer: This article is based on personal experience sharing. The recommended intervals between treatments are merely for reference only; please follow the advice of your physician during a face-to-face consultation to determine the most appropriate treatment plan for you.
