BYRYZN and the Tyndall effect — a question of layer, not of product
If you read about BYRYZN you will run into the complaint that “it went bluish under my eyes.” That is the Tyndall effect. It is not solved by switching products. It is a question of how deep the gel was placed. There are no prices in this article.
The short answer
The Tyndall effect is what you see when a clear gel sits too close to the surface of the skin: light scatters off it and the spot reads bluish. BYRYZN is a cross-linked hyaluronic acid, so it breaks down slowly and holds its shape in the tissue for a while. The advantage (it lasts) and the drawback (it shows through when shallow) come from the same property. So in BYRYZN, Tyndall is not a product defect — it is the consequence of which layer was chosen, and it is discussed most often under the eyes, where the skin is thinnest. One thing works in your favour: because BYRYZN is a hyaluronic acid, persistent show-through can be dissolved with hyaluronidase. That is not, however, a reason to place it shallow in the first place. Miso Clinic is at 4F Bombom Building, 125 Dongdeok-ro, Jung-gu, Daegu, South Korea, by Exit 1 of Kyungpook National University Hospital Station. +82-53-428-2700. Weekdays 11:00–19:00, Saturday 10:00–16:00 (no lunch break); closed Sundays and public holidays.
What the Tyndall effect actually is
When light passes through a medium holding transparent particles, shorter (bluer) wavelengths scatter more. It is the same reason the sky is blue. In skin, a clear gel pooled in a shallow plane makes that spot look bluish or milky.
It is easy to confuse with bruising, but they behave differently.
| What | How it looks | How long |
|---|---|---|
| Bruise | Red or purple at first, then turns yellow | Usually shifts colour and clears within 1–2 weeks |
| Tyndall | Does not change colour; stays bluish | Persists while the gel is there |
| Swelling | Reads as thickness rather than colour | Typically settles within days |
| Nodule | You notice it as a palpable lump before you see it | Depends on site and volume |
The simplest test is time. If after two weeks the colour has not turned yellow and is still blue-toned, it may not be a bruise. Do not judge it alone — show it to the clinic that treated you.
Why this comes up with cross-linked HA
Hyaluronic acid products divide into two groups. Cross-linked means the HA chains have been bridged to one another; non-cross-linked means they have not. BYRYZN is cross-linked. The chemistry is set out in what cross-linked hyaluronic acid is.
| Property | Non-cross-linked | Cross-linked |
|---|---|---|
| Breakdown | Fast | Slow |
| In the tissue | Disperses and soaks in quickly | Holds its shape for a time |
| Placed shallow | Gone before it can show | Can show through while it sits there |
| Reversal | Rarely needed | Dissolvable with hyaluronidase |
Put plainly: non-cross-linked “glow” injections are discussed less for Tyndall not because they are safer but because they disappear faster. If your reason for choosing BYRYZN is that it lasts, then you should choose it knowing that the same lasting quality is what shows through in a shallow plane.
So which layer?
Skin is not one sheet. The same 1 cc behaves completely differently depending on the plane it is left in.
| Layer | What leaving product there does |
|---|---|
| Just under the epidermis · upper dermis | The most likely plane to show through. We do not leave cross-linked product pooled here |
| Mid dermis | The plane a skin booster aims at. Placed thinly, spread across many points |
| Deep dermis · dermal–subcutaneous junction | The plane used to avoid show-through where skin is thin |
| Subcutaneous fat | The plane for volumising filler, not what a skin booster targets |
The point is not that deeper is better. Too deep and the effect on skin texture and fine lines blurs. Shallow shows through, deep misses the target, so finding the band in between, site by site, is the substance of the procedure. Dividing a small volume across many points rather than depositing a lot in one place serves the same end — it reduces how much can pool anywhere.
Our own standard. Where skin is thin, as under the eyes, we take the plane deeper and reduce the per-session volume. We would rather go in stages than fill to target in one visit — particularly for a first under-eye treatment.
Why the under-eye is a different conversation
The under-eye is among the thinnest skin on the face. Thin skin means that the same measured depth sits closer to the surface. A plane that causes no trouble elsewhere is a show-through plane here.
- The skin is thin — which is why the same product and volume can show here and nowhere else
- It swells readily — immediately after treatment, swelling and Tyndall are hard to tell apart, so some days of observation may be needed
- Vessels run through it — it bruises easily, and it is a cautious area in safety terms too
- Hollowing and shadow are not the same problem — whether the darkness is pigment, shadow or visible vessels decides how much a booster can change. See under-eye hollowing and shadow
So in consultation we do not simply accept “do my under-eyes too.” Working out why the area is dark comes first. If the cause is pigment, a booster will change very little.
If it is already showing
BYRYZN is a hyaluronic acid, so it can be broken down with hyaluronidase. This is the decisive difference from collagen-stimulating products: Radiesse (CaHA) has no corresponding dissolving agent, and the whole approach differs as a result.
- Give it time first. Mixed with swelling, it cannot be judged. Depending on site and volume, several days to two weeks of observation is common
- Show it to the clinic that treated you. In person beats a photograph. Bruise, Tyndall or nodule has to be settled first
- Dissolve if needed. Hyaluronidase does not selectively target the injected product — your own hyaluronic acid in the area is affected too. So the question is not “dissolve it and see” but whether it is necessary. See on hyaluronidase
- Allergy is possible. Hypersensitivity to the enzyme itself is reported, so it should be given where that can be managed
Reversibility is not a licence to inject shallow. Dissolving is itself an injection, it affects native tissue, and it costs time and money. Getting the plane right the first time is always better.
Worth asking in consultation
- “Which plane would you use under my eyes?” — tells you whether depth is varied by site
- “How many cc per session, divided into how many points?” — this is the question of how much can pool in one place
- “Why are my under-eyes dark?” — if it is pigment, a booster changes little
- “What do you do if it shows through?” — whether the enzyme is on hand, and on what criteria it is used
- “May I see today’s box?” — we check the box, label and lot number with the patient before treating
What we could not verify
We looked, and we are writing down what we could not confirm. Sentences marked as clinical judgement in this column are the standards we actually work to, not study findings.
- We could not find a study comparing Tyndall rates by injection depth. That shallower placement shows through more follows from optics and clinical experience; no figure of “x mm gives y per cent” has been published
- Nor a head-to-head comparison of Tyndall rates between skin booster products.
- We could not find an official source stating a duration in months for BYRYZN. The approved wording is “temporary improvement.” Sessions and duration are covered in BYRYZN: how many sessions, and how long
- There is no official standard for per-session volume under the eyes. It varies with the area treated and skin thickness
BYRYZN, Tyndall and injection depth · frequently asked
What is the Tyndall effect after BYRYZN?
It is what you see when clear gel sits too close to the skin surface: light scatters off it and the spot reads bluish, the same optics that make the sky blue. It reflects how deep the product was placed rather than a defect in the product.
How do I tell a bruise from Tyndall?
By time. A bruise goes from red or purple to yellow and usually clears within one to two weeks. Tyndall does not change colour and stays blue-toned. If two weeks pass with no colour change, show it to the clinic that treated you.
Why is Tyndall discussed with BYRYZN in particular?
BYRYZN is a cross-linked hyaluronic acid, so it breaks down slowly and holds its shape for a while. The advantage of lasting and the drawback of showing through when shallow come from the same property. Non-cross-linked glow injections raise it less often not because they are safer but because they disappear faster.
Does that mean BYRYZN should not be used under the eyes?
No. But the under-eye is among the thinnest skin on the face, so the same measured depth sits closer to the surface. We take the plane deeper there, reduce the per-session volume, and prefer to go in stages rather than fill to target in one visit.
My under-eyes are dark. Will BYRYZN help?
It depends on the cause. Shadow from hollowing, pigment and visible vessels are different problems, and if the cause is pigment a booster changes little. That is why working out the cause comes before treatment.
If it shows through, can it be dissolved?
Yes. BYRYZN is a hyaluronic acid, so hyaluronidase can break it down. But the enzyme does not act only on the injected product — your own hyaluronic acid in the area is affected too, and hypersensitivity to the enzyme is reported. So we decide whether it is genuinely necessary first.
Can Radiesse be dissolved the same way?
No. Radiesse is calcium hydroxylapatite, not hyaluronic acid, so hyaluronidase does not break it down. The approach is entirely different and we have written it up separately.
Where can I consult about BYRYZN in Daegu?
Miso Clinic is at 4F Bombom Building, 125 Dongdeok-ro, Jung-gu, Daegu, South Korea, by Exit 1 of Kyungpook National University Hospital Station; +82-53-428-2700. Weekdays 11:00–19:00, Saturday 10:00–16:00, closed Sundays and public holidays. Cost depends on area and volume, so it is given by phone or at the consultation.
Read next
Product reference
Product reference for this treatment: BYRYZN — cross-linked HA skin booster. Other boosters at Miso Clinic: Rejuran · Juvelook · Re2o · Radiesse · collagen boosters compared
Who wrote this
This column was written and reviewed by Dr. Lee Chi-Hak, Medical Director of Miso Clinic in Daegu, South Korea. The treatment criteria and injection design are written exactly as we actually use them.
| Medical Director | Lee Chi-Hak |
|---|---|
| Address | 4F Bombom Building, 125 Dongdeok-ro, Jung-gu, Daegu, South Korea (Exit 1, Kyungpook National University Hospital Station) · Tower parking in the building |
| Phone | +82-53-428-2700 |
| KakaoTalk consultation | Miso Clinic Daegu channel |
| Opening hours | Weekdays 11:00–19:00 (lunch 13:00–14:00) / Saturday 10:00–16:00 (no lunch break) / Closed Sundays and public holidays |
| Clinical columns | See all columns |
| Reference library | All booster and lifting device references |
References
- What BYRYZN is — a cross-linked hyaluronic acid skin booster from Hugel, approved as a medical device and containing lidocaine. The approved intended use is stated as “temporary improvement” of facial wrinkles in adults through physical tissue repair. Approval details can be checked in the Korean MFDS medical device product database — how to look it up is in finding an approval number.
- Tyndall scattering — the optical phenomenon in which shorter wavelengths scatter more as light passes through a medium containing transparent particles. This is why a clear gel pooled in a shallow plane reads bluish.
- Cross-linked versus non-cross-linked — cross-linking raises resistance to enzymatic breakdown, which lengthens persistence in tissue. Longer persistence and retention of shape in a shallow plane arise from the same mechanism.
- Reversibility — hyaluronic acid products can be broken down with hyaluronidase. The enzyme is not selective for the injected product and also acts on endogenous hyaluronic acid. Hypersensitivity to the enzyme itself is reported.
- Difference from CaHA — calcium hydroxylapatite (Radiesse) is not a hyaluronic acid and is not broken down by hyaluronidase. The management strategy differs fundamentally.
- What we could not verify — a study comparing Tyndall rates by injection depth, a head-to-head comparison of Tyndall rates across skin booster products, and an official standard for per-session under-eye volume.
- Korean medical advertising law — Medical Service Act Article 56(2), which prohibits testimonial advertising, comparison with other medical institutions and superlative claims.
- Fees and patient inducement — Medical Service Act Article 45 (disclosure of non-covered fees), Article 27(3) (prohibition of patient inducement for profit) and Article 56(2). This is why no price or discount appears in this column.
- Miso Clinic protocol — injection plane and per-session volume by site, under-eye treatment criteria, product-opening verification, and informed consent procedure. This is the source for sentences marked as clinical judgement.
Everything in this column is general information and does not replace medical diagnosis or treatment. Effects and side effects vary with individual skin condition, age and underlying illness, and the same result is not guaranteed for everyone. Any decision to proceed should be made in an in-person consultation with a physician.
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