The Lab – Aesthetics Science & Insights – Page 9 – Creative Touch

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The Lab

Where beauty meets biology

The Science Library

Testosterone
MolecularEntity
Primary androgen hormone affecting hair follicles, with elevated free testosterone contributing to androgenetic hair loss.
Thulium Fractional Laser
MedicalTherapy
Gentle fractional laser using 1927nm wavelength, treating photoaging, dyspigmentation, acne scarring, and non-facial photodamage whilst restoring barrier lipid synthesis pathways
Thymic stromal lymphopoietin
Protein
A keratinocyte‑derived alarmin that translates barrier disruption into Th2 immune activation, driving itch, mast‑cell priming, and the atopic inflammatory cascade.
Thyroid dysfunction
MedicalCondition
Condition affecting hair growth cycles, worth investigating when experiencing unexplained hair changes.
Thyroid hormone
ChemicalSubstance
Metabolic hormones produced by the thyroid gland, with imbalances affecting hair growth cycles and skin quality.
Tight Junction
AnatomicalStructure
Tight junctions are intercellular protein complexes that form continuous belt-like seals at cell–cell contacts in epithelial tissues.
Tirzepatide
Drug
Dual GLP-1/GIP receptor agonist (Mounjaro/Zepbound) providing powerful appetite suppression through weekly subcutaneous injection.
Tissue regeneration
BiologicalProcess
Repair outcomes range from true regeneration to fibrosis, determined by TGFβ isoform balance, macrophage M1→M2 transition, and inflammageing-related suppression of progenitor cells.
Topical steroid withdrawal
MedicalCondition
A drug‑related dermatosis in which prolonged topical steroid use leads to burning, erythema, and severe barrier dysfunction after withdrawal, often misdiagnosed as worsening eczema.
Transepidermal water loss
BiologicalProcess
Transepidermal water loss (TEWL) is the passive diffusion of water vapour through the epidermis and stratum corneum to the skin surface, where it evaporates into the surrounding air.
Transforming growth factor beta
Protein
TGF-β is a pleiotropic cytokine and the master regulator of wound healing, fibrosis, and extracellular matrix remodelling in skin.
Tumour necrosis factor
Protein
TNF is a pro-inflammatory cytokine produced by macrophages, adipocytes, and T-cells that acts through NF-κB to amplify and sustain inflammatory signalling.
Type 2 diabetes
MedicalCondition
Metabolic condition characterised by insulin resistance and elevated blood glucose, for which Mounjaro is an approved treatment.
Vascular endothelial growth factor
BioChemEntity
The primary angiogenic growth factor in skin, produced by keratinocytes, dermal fibroblasts, and dermal papilla cells and stored in platelet alpha granules.
Vermilion border
AnatomicalStructure
The red-coloured portion of lips, uniquely vulnerable due to thin barrier, absent sebum production, and minimal melanin.
Vitamin A
ChemicalSubstance
Fat‑soluble vitamin whose active form (ATRA) regulates thousands of genes via nuclear receptors to drive epidermal renewal, boost collagen, suppress MMPs, and balance sebum.
Vitamin B12
ChemicalSubstance
Water‑soluble vitamin whose cofactor roles in methylation and fatty‑acid metabolism make deficiency visible as acral hyperpigmentation, hair changes, and barrier fragility.
Vitamin B3
ChemicalSubstance
Water-soluble B vitamin whose cosmeceutically active derivative - niacinamide (nicotinamide) - is the primary form relevant to skin biology
Vitamin C
MolecularEntity
Water‑soluble vitamin that stabilises collagen by supporting hydroxylation enzymes and suppresses UV‑driven ROS that trigger MMP‑1 collagen breakdown.
Vitamin D
ChemicalSubstance
Fat‑soluble secosteroid whose active form (calcitriol) is made in the epidermis and, via VDR, regulates keratinocyte differentiation, antimicrobial peptides, barrier function, and innate immunity.
Vitamin E
ChemicalSubstance
Fat‑soluble antioxidant concentrated at the skin surface, where it blocks UV‑driven lipid peroxidation and squalene oxidation; regenerated by vitamin C, making them a coupled antioxidant system.
Vitamin K
ChemicalSubstance
Fat‑soluble vitamin whose K1 and K2 forms share a GGCX‑dependent mechanism. K1 supports coagulation for wound repair, while K2 prevents elastin calcification and dermal stiffening.
Vitreoscilla filiformis
BioChemEntity
A TLR2‑activating bacterial lysate that boosts epidermal AMP and antioxidant genes and improves barrier function and S. aureus colonisation in atopic dermatitis.
Vomiting
MedicalSignOrSymptom
GI side effect of tirzepatide showing dramatic variation by injection site, with thigh injection reducing incidence by more than half.
Weight regain after GLP-1 cessation
MedicalCondition
Discontinuation of GLP-1 receptor agonists produces rapid, substantial weight regain driven by the reassertion of the biological mechanisms the drug was suppressing.