Spicule Serums and VT Reedle Shot: How "Microneedling in a Bottle" Works, Which Strength to Choose, and Who Should Avoid It

Quick answer

Spicules are microscopic, needle-shaped silica fragments taken from sponges. Certain spicules can physically perturb the outer skin barrier. Laboratory models show increased penetration of some test molecules, which helps explain the tingling and interest in delivery technology. The scale and duration of this effect for each shop-bought formula in people is not established.

VT Cosmetics' Reedle Shot is the best-known spicule range, sold in strengths 50, 100, 300, 700 and 1000. There is meaningful preclinical evidence of enhanced delivery for certain sponge-spicule preparations. Independent clinical evidence for cosmetic spicule serums is still thin. They are not equivalent to professional microneedling.

In this guide

• What are spicules?
• How spicules work on skin
• What the evidence shows
• What is demonstrated in the laboratory — and what is not
• Is it safe?
• VT Reedle Shot strengths compared
• Example three-week introduction — not a manufacturer prescription
• Spicules vs professional microneedling
• How to use a spicule serum safely
• Who should avoid spicule serums
• Frequently asked questions
• UK buying checklist and side-effect decision tree
• References

What are spicules?

Spicules are the skeleton of sea and freshwater sponges. Each one is a hard, glass-like rod of silica. On cosmetic labels they can appear as Hydrolyzed Sponge or sponge-derived extracts, or simply as Silica, which is what VT's own ingredient list shows. VT calls its version CICA Reedle and pairs it with centella. Sponges are animals, so sponge-derived spicules are not vegan; VT's list does not state the source of its silica, so ask the brand if that matters to you.

The spicules studied most in research come from a marine sponge, Haliclona sp. They measure about 120 micrometres (µm) long and 7 µm wide (Zhang et al., 2017). Freshwater sponge spicules used in Korean cosmetics research are about 250 µm long and 12 µm wide (Kim et al., 2022). For scale, a human hair is about 70 µm wide.

How spicules work on skin

1. Penetrate the outer layer. When you massage the serum in, the rods push into the stratum corneum, the skin's dead outer layer.
2. Open micro-channels. In pig-skin experiments, Haliclona spicules created about 850 channels per square millimetre, each about 49 µm deep (Zhang et al., 2019).
3. Stay in place for days. Spicules remained in skin for at least 72 hours in one lab model, and channels took up to 120 hours (five days) to close in another.
4. Boost penetration of what follows. Delivery of test molecules into skin rose many-fold. That is why the after-routine matters so much.
5. Trigger a mild renewal response. The micro-injury and surface exfoliation are thought to drive the smoother texture users report.

Our reading of the evidence: spicules are being investigated as a delivery approach; skin-model data do not prove that every consumer serum increases absorption for days. Irritants layered with a prickling formula may also increase discomfort, which is why a simple accompanying routine is sensible.

What the evidence shows

Most spicule research is pharmaceutical. It uses spicules to deliver drugs through skin, not to treat texture.

What's missing: there are no independent, randomised, placebo-controlled trials of Reedle Shot or similar products for wrinkles, scars or pores. Brand "clinically tested" claims usually refer to small, unpublished in-house studies. Treat texture and glow results as plausible, not proven.

What is demonstrated in the laboratory — and what is not

The commonly cited 2017 marine-spicule experiment evaluated delivery into porcine skin, including a measured change for a model 10 kDa dextran molecule. It was not an independent clinical trial proving that Reedle Shot 100 makes human wrinkles or acne scars disappear. The 2022 Korean spicule paper describes a delivery-system approach, and its authors are employees of Pion-Tech, a company developing the technology. Neither fact invalidates the experiments; both matter when assessing how far to generalise. 2017 skin-delivery study · 2022 cosmetic delivery paper.

For a shopper, the sensible hierarchy is published clinical outcomes for the exact product first, then ingredient or formulation trials, then laboratory models, and lastly manufacturer testimonials. Tingling is a sensory effect, not an efficacy endpoint.

Is it safe?

Some people tolerate a spicule serum on intact skin, but high-quality adverse-event data for each retail formula are lacking. Tingling, prickling and short-lived redness are expected. Burning that lasts, swelling, rash or broken skin are not. Stop if they happen.

The main risks come from what spicules allow in:

• Irritation from layered actives. Retinoids, acids and strong vitamin C can sting badly on spicule-treated skin.
• Allergy. More allergen reaches living skin. Reedle Shot 100 also contains propolis, a bee product and a known contact allergen.
• Infection. Never apply over spots that are open, cold sores or broken skin.
• Sun exposure. Sun protection is a good baseline precaution; evidence that this product causes measurable photosensitivity is limited.

VT Reedle Shot strengths compared

The brand uses numbers to distinguish its products and intensity, but these are not a standardised, independently validated measure of spicule dose or clinical effect. Treat the branded numbers as range identifiers, not validated spicule doses or directly comparable concentrations. Always refer to the instructions for the exact version and market.

VT also markets variants; check the exact box because supporting ingredients and precautions vary: Collagen Reedle Shot, PDRN Reedle Shot, Vita-Light (vitamin C) Reedle Shot and Hydrop Reedle Shot. These change the supporting ingredients, not the basic spicule mechanism.

Reedle Shot 100 ingredients (VT's official list; check your box): water, dipropylene glycol, glycerin, niacinamide, butylene glycol, macadamia seed oil, silica, adenosine, sodium hyaluronate, centella asiatica extract with asiaticoside, madecassoside, madecassic acid and asiatic acid, propolis extract and a blend of amino acids. No fragrance is listed, but check the current UK INCI. Source: VT Cosmetics.

Decision rule: do not escalate solely because a higher number exists. There is no reliable head-to-head evidence that a higher number produces superior visible results in an average user.

Example three-week introduction — not a manufacturer prescription

VT's specific published directions describe Reedle Shot 100 as suitable for daily use and Reedle Shot 300 every three days. These are manufacturer instructions, not proof that daily use is necessary or ideal for everyone. VT also says not to combine 100, 300 or 700 together, not to use its Reedle products with beauty devices, and not to apply immediately after dermatological procedures. Official 100 · Official 300.

Spicules vs professional microneedling

Spicule serums are not a substitute for clinic microneedling for deep acne scars. They are marketed for texture and glow, but independent efficacy trials remain limited. Do not use on recently treated skin. Ask the clinician performing needling, laser or a peel how long to stop beforehand and when it is safe to restart; there is no universal evidence-based one-week interval.

How to use a spicule serum safely

1. Patch test cautiously. Test a small area according to the product instructions and do not proceed if it causes marked or persistent irritation.
2. Cleanse and dry the skin. VT's directions place Reedle Shot as the first step of an evening routine.
3. Use only the amount on the current product label. Massage or pat gently as directed; do not deliberately scrub hard.
4. Avoid the eyes and lips. Wash your hands afterwards so you don't transfer spicules to your eyes.
5. Follow with something bland. A fragrance-free hydrating serum or a ceramide moisturiser is ideal. See our layering order guide.
6. Keep strong actives for other nights. That means retinoids, AHAs, BHAs, benzoyl peroxide and high-strength vitamin C.
7. Wear SPF 30+ the next morning. Do the same on the days after, too.
8. Don't rush to a higher number. Judge the strength you're on over a few weeks, and only move up if your skin is comfortable and you want more effect.

If you stop for a bad reaction, switch to a minimal routine (cleanser, barrier cream, SPF) until your skin settles. Our ceramides guide covers barrier repair.

Who should avoid spicule serums

• Active acne with open or inflamed spots, eczema, psoriasis flares, rosacea flares or sunburn
• Cold sores, or a history of frequent cold sores, unless you avoid the lip area
• Anyone using prescription retinoids such as tretinoin or adapalene, or taking isotretinoin, without their prescriber's agreement
• People allergic to bee products, because some Reedle Shots contain propolis
• Anyone who has recently had a peel, laser or microneedling, until their practitioner says it's safe to restart

Pregnancy and breastfeeding: there are no safety data. Some formulations include additional active ingredients, and spicules may increase absorption of whatever else you apply. Check the exact INCI and discuss it with your midwife, GP or pharmacist first.

Frequently asked questions

Do spicules stay in your skin?

At least one laboratory investigation of a particular marine-spicule preparation observed persistence for 72 hours; the residence time of individual cosmetic formulations on human skin is not known.

Is the tingling a sign it's working?

It shows the spicules are in the skin. It doesn't prove results. More tingle isn't better.

Can I use Reedle Shot with retinol?

Not on the same night. Alternate them, and stop both if your skin becomes sore. Our retinoids guide explains how to schedule them.

Can I use Reedle Shot with PDRN?

The combination is marketed, but better delivery or results have not been established in clinical trials. If you pair products, introduce them separately and stop if irritation develops. See our PDRN ampoules guide.

Does Reedle Shot help acne scars?

Evidence of benefit for established acne scars is insufficient. Deep or rolling scars need professional treatment.

Is Reedle Shot vegan?

Don't assume so. Sponge-derived spicules are animal-derived, and VT's ingredient list shows silica without stating its source. Ask the brand if this matters to you.

Which Reedle Shot should I buy first?

If you choose to try this category, a milder option and conservative frequency make more sense than immediately selecting the strongest; avoid the category during a barrier flare.

UK buying checklist and side-effect decision tree

Before purchasing, identify the exact variant, read the manufacturer usage instructions, check UK Responsible Person details and determine whether your routine already includes strong exfoliants or prescription acne treatment. A name such as “Cica” or “PDRN” does not guarantee that a product is soothing. Supporting ingredients differ between variants, so the current INCI is the source of truth.

If it tingles briefly but skin remains comfortable: follow the label and avoid over-layering. If it repeatedly burns or peels: stop and return to gentle cleanser, moisturiser and SPF. If there is significant swelling, blistering, weeping, eye exposure or signs of infection: seek medical advice promptly. Do not try to force the spicules out with abrasive scrubbing.

Bottom line: spicule delivery is scientifically interesting, but the gap between laboratory penetration findings and proven cosmetic results remains wide. The most credible advice is to choose conservatively, avoid stacking and judge the actual benefit against irritation.

References

Research references below were retrieved via PubMed.

1. Zhang et al. Skin delivery of hydrophilic biomacromolecules using marine sponge spicules. Mol Pharm. 2017. doi:10.1021/acs.molpharmaceut.7b00468
2. Zhang et al. Skin delivery of hyaluronic acid by the combined use of sponge spicules and flexible liposomes. Biomater Sci. 2019. doi:10.1039/c8bm01555d
3. Kim et al. A novel dermal delivery system using natural spicules for cosmetics and therapeutics. J Cosmet Dermatol. 2022. doi:10.1111/jocd.14771
4. Zhang et al. Topical delivery of lidocaine using spicules for local anesthesia. Drug Deliv Transl Res. 2025. doi:10.1007/s13346-025-02030-4
5. Zhang et al. Enhanced skin delivery of therapeutic peptides using spicule-based topical delivery systems. Pharmaceutics. 2021. doi:10.3390/pharmaceutics13122119
6. Cosmetics Business. Spicules: the K-beauty skin care ingredient primed to break through in 2026. 4 March 2026.
7. VT Cosmetics. Reedle Shot 100 and Reedle Shot 300 official product directions.

How we researched this guide

This guide is based on peer-reviewed studies (retrieved via PubMed), UK regulatory and NHS guidance, and manufacturer or retailer information, which we identify as such wherever it is cited. Products named here have not been tested hands-on by us. The guide was medically reviewed by Khalid Anwar, GPhC-registered pharmacist, on 30 October 2026. It is general information, not individual medical advice. Spotted an error? Tell us via our corrections page.