Cat. No.: HY-18341

L-Thyroxine

(Synonyms: Levothyroxine; T4)

13 Cited Publications

Customer Review

Based on 13 publication(s) in Google Scholar

L-Thyroxine (Levothyroxine; T4) is a synthetic hormone for the research of hypothyroidism. DIO enzymes convert biologically active thyroid hormone (Triiodothyronine,T3) from L-Thyroxine (T4).

For research use only. We do not sell to patients.

Purity: 98.43%
CAS No.: 51-48-9
Formula: C₁₅H₁₁I₄NO₄
Molecular Weight:776.87

Storage:

Powder -20°C, 3 years , 4°C, 2 years ; In solvent -80°C, 6 months , -20°C, 1 month

L-Thyroxine Chemical Structure

CAS No.: 51-48-9

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Fluorescent Dye

Strong Fluorescence Signal / Multi-Disciplinary Applications / High Fluorescence Specificity

Biological Activity
- Description
- IC₅₀ & Target
- Cellular Effect
- In Vivo
Chemical Information
Publications (13)
Solvent & Solubility
- In Vitro
- In Vivo
Protocol
Purity & Documentation
References
Help & FAQs
Bioz

Biological Activity

Description

L-Thyroxine (Levothyroxine; T4) is a synthetic hormone for the research of hypothyroidism. DIO enzymes convert biologically active thyroid hormone (Triiodothyronine,T3) from L-Thyroxine (T4)^[1].

IC₅₀ & Target

Human Endogenous Metabolite

All Endogenous Metabolite Isoforms :

Cellular Effect

Cell Line	Type	Value	Description	References
HEK293	IC₅₀	4.9 μM Compound: Levothyroxine	Inhibition of human recombinant UGT1A1 expressed in HEK293 cells assessed as reduction in bilirubin glucuronidation by LC-MS/MS method Inhibition of human recombinant UGT1A1 expressed in HEK293 cells assessed as reduction in bilirubin glucuronidation by LC-MS/MS method	[PMID: 21030469]
HEK293	IC₅₀	5.6 μM Compound: Levothyroxine	Inhibition of human recombinant UGT1A1 expressed in HEK293 cells assessed as reduction in estradiol 3-glucuronidation by LC-MS/MS method Inhibition of human recombinant UGT1A1 expressed in HEK293 cells assessed as reduction in estradiol 3-glucuronidation by LC-MS/MS method	[PMID: 21030469]
HEK-293T	EC₅₀	12 μM Compound: T4	Agonist activity at recombinant human pFA-CMV fused PPARgamma expressed in HEK293T cells transfected with pFR-luciferase plasmid and pRL-SV40 plasmid incubated for 14 to 16 hrs by dual glo luciferase reporter gene assay Agonist activity at recombinant human pFA-CMV fused PPARgamma expressed in HEK293T cells transfected with pFR-luciferase plasmid and pRL-SV40 plasmid incubated for 14 to 16 hrs by dual glo luciferase reporter gene assay	[PMID: 32356658]
HEK-293T	EC₅₀	15.4 μM Compound: T4	Agonist activity at recombinant human pFA-CMV fused RXRalpha LBD expressed in HEK293T cells transfected with pFR-luciferase plasmid and pRL-SV40 plasmid incubated for 14 to 16 hrs by dual glo luciferase reporter gene assay Agonist activity at recombinant human pFA-CMV fused RXRalpha LBD expressed in HEK293T cells transfected with pFR-luciferase plasmid and pRL-SV40 plasmid incubated for 14 to 16 hrs by dual glo luciferase reporter gene assay	[PMID: 32356658]
HepG2	EC₅₀	100 μM Compound: Levothyroxine	Activation of human PXR expressed in human HepG2 (DPX-2) cells assessed as induction of CYP3A4 after 24 hrs by luminescent analysis Activation of human PXR expressed in human HepG2 (DPX-2) cells assessed as induction of CYP3A4 after 24 hrs by luminescent analysis	[PMID: 20966043]
MDCK	IC₅₀	8 μM Compound: Thyroxine	TP_TRANSPORTER: inhibition of Triiodothyronine uptake in OATP4C1-expressing MDCK cells TP_TRANSPORTER: inhibition of Triiodothyronine uptake in OATP4C1-expressing MDCK cells	[PMID: 14993604]

In Vivo

Deiodinases (DIOs), which catalyse the conversion of thyroxine (pro-hormone) to the active thyroid hormone, are associated with thyroid stimulating hormone (TSH) levels. DIO1 and DIO2 catalyze activation of thyroid hormone secretion in contrast to DIO3 playing role inactivation of the secretion. Activities of DIO1 and DIO2 play pivotal role in the negative feedback regulation of pituitary TSH secretion^[1]. L-Thyroxine (T4) and Triiodothyronine (T3) hormones are known to modulate the expression of ionic channels, pumps and regulatory contractile proteins. Moreover, thyroid hormones have been shown to influence calcium homeostasis and flux responsible for excitation and contractility, with L-Thyroxine and Triiodothyronine modulating its pharmacological control and secretion. In rats fed 12 weeks with the iodine-free diet, a significant decrease in the levels of both Triiodothyronine and L-Thyroxine is observed when compared to the control group fed with standard diet (p<0.001). In the group treated with low doses of L-Thyroxine, an increase in L-Thyroxine levels is observed (p=0.02) while Triiodothyronine levels remain virtually similar to the control group (p=0.19). Rats treated with high doses of L-Thyroxine display a significant increase in both Triiodothyronine and L-Thyroxine circulating concentrations compared to the non-treated hypothyroid group (p<0.001 and p=0.004, respectively) and a significant increase in L-Thyroxine levels when compared to the control values (p=0.03)^[2].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

Chemical Information

CAS No. 51-48-9
Appearance Solid
Molecular Weight 776.87
Formula C₁₅H₁₁I₄NO₄
Color White to light yellow
SMILES

N[C@@H](CC1=CC(I)=C(C(I)=C1)OC2=CC(I)=C(O)C(I)=C2)C(O)=O
Synonyms

Levothyroxine; T4
Structure Classification
- Phenols
- Monophenols
- Ketones, Aldehydes, Acids
Initial Source
Shipping

Room temperature in continental US; may vary elsewhere.

Storage

Powder	-20°C	3 years
	4°C	2 years
In solvent	-80°C	6 months
	-20°C	1 month

Publications (13)

All In Vivo Efficacy StudyHistological Imaging/StainingIn Vivo Imaging

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Journal Impact Factor

Cell

Restoring circadian rhythms in the hypothalamic paraventricular nucleus reverses aging biomarkers and extends lifespan in male mice. [Abstract]

2026 Apr 2;189(7):2007-2023.e20. PMID: 41785851
Nat Immunol

A method for predicting drugs that can boost the efficacy of immune checkpoint blockade. [Abstract]

2024 Apr;25(4):659-670. PMID: 38499799
Cell Rep Med

Profiling the metabolome of uterine fluid for early detection of ovarian cancer. [Abstract]

2023 Jun 20;4(6):101061. PMID: 37267943
EMBO J

Whole-body replacement of larval myofibers generates permanent adult myofibers in zebrafish. [Abstract]

2024 Aug;43(15):3090-3115. PMID: 38839992

L-Thyroxine purchased from MedChemExpress. Usage Cited in: EMBO J. 2024 Aug;43(15):3090-3115. [Abstract]

Timeline and three different Thyroxine hormone (T4) treatment schemes. RT-qPCR analysis of the whole-animal myofiber loss for each of the schemes.
Europace

Fto-mediated m6A demethylation of Lox drives atrial fibrosis and promotes atrial fibrillation in a murine model of hyperthyroidism. [Abstract]

2026 Mar 30;28(4):euag047. PMID: 41812233
J Drug Deliv Sci Technol

2023 Sep 28, 105008.
Stem Cell Rev Rep

Satellite Glial Cells Give Rise to Nociceptive Sensory Neurons. [Abstract]

2021 Jun;17(3):999-1013. PMID: 33389681
Sci Rep

The iodide transporter Slc26a7 impacts thyroid function more strongly than Slc26a4 in mice. [Abstract]

2022 Jul 4;12(1):11259. PMID: 35788623

L-Thyroxine purchased from MedChemExpress. Usage Cited in: Sci Rep. 2022 Jul 4;12(1):11259. [Abstract]

Growth curve of male wild type (WT), Slc26a7^+/−, Slc26a7^−/−, and Slc26a7^-/− mice receiving L-Thyroxine (drinking water containing 0.39 mg/L L-Thyroxine) replacement from day 21 with a low iodine diet. Note that Slc26a7^−/− mice without thyroid hormone replacement did not survive.
Clin Exp Med

The impact of hyperthyroidism on the hematopoietic system. [Abstract]

2025 Dec 20. PMID: 41420729
Dis Model Mech

Compromised COPII vesicle trafficking leads to glycogenic hepatopathy in zebrafish. [Abstract]

2024 Aug 14:dmm.050748. PMID: 39139065
Mol Brain

iTRAQ-based proteomic profiling reveals protein alterations after traumatic brain injury and supports thyroxine as a potential treatment. [Abstract]

2021 Jan 27;14(1):25. PMID: 33504361

L-Thyroxine purchased from MedChemExpress. Usage Cited in: Mol Brain. 2021 Jan 27;14(1):25. [Abstract]

Effects of L-Thyroxine on histopathology post-TBI. a Brain sections stained with cresyl violet were shown on the left. Lesion volume was calculated from the sections.

L-Thyroxine purchased from MedChemExpress. Usage Cited in: Mol Brain. 2021 Jan 27;14(1):25. [Abstract]

Brain water content of traumatized hemisphere increased 1 day post-TBI, whereas L-Thyroxine alleviates edema.

L-Thyroxine purchased from MedChemExpress. Usage Cited in: Mol Brain. 2021 Jan 27;14(1):25. [Abstract]

BBB integrity was reflected by detecting the extravasation of EB dye (n = 3 per group).
Ther Deliv

Excipient adjusting rheological properties of silica-based injectable hydrogel composites for controlled drug delivery. [Abstract]

2025 Oct 30:1-15. PMID: 41168137
Aalto University

2026.

Solvent & Solubility

In Vitro:

DMSO : 233.33 mg/mL (300.35 mM; Need ultrasonic; Hygroscopic DMSO has a significant impact on the solubility of product, please use newly opened DMSO)

1M NaOH : 5 mg/mL (6.44 mM; ultrasonic and warming and adjust pH to 11 with NaOH and heat to 60°C)

H₂O : < 0.1 mg/mL (insoluble)

View the Complete Stock Solution Preparation Table

Preparing Stock Solutions

View the Complete Stock Solution Preparation Table

Concentration Solvent Mass

1 mg

5 mg

10 mg

Concentration

Solvent

Mass

1 mM

1.2872 mL

6.4361 mL

12.8722 mL

5 mM

0.2574 mL

1.2872 mL

2.5744 mL

10 mM

0.1287 mL

0.6436 mL

1.2872 mL

Please refer to the solubility information to select the appropriate solvent. Once prepared, please aliquot and store the solution to prevent product inactivation from repeated freeze-thaw cycles.

Storage method and period of stock solution: -80°C, 6 months; -20°C, 1 month. When stored at -80°C, please use it within 6 months. When stored at -20°C, please use it within 1 month.

Molarity Calculator

Mass (g) = Concentration (mol/L) × Volume (L) × Molecular Weight (g/mol)

Mass Mass

Concentration Concentration

Volume Volume

Molecular Weight Molecular Weight

Dilution Calculator

Concentration _(start) × Volume _(start) = Concentration _(final) × Volume _(final)

Concentration _(start) Concentration _(start)

Volume _(start) Volume _(start)

Concentration _(final) Concentration _(final)

Volume _(final) Volume _(final)

In Vivo:

Select the appropriate dissolution method based on your experimental animal and administration route.

Stock Solution Working Solution

For the following dissolution methods, please ensure to first prepare a clear stock solution using an In Vitro approach and then sequentially add co-solvents:
To ensure reliable experimental results, the clarified stock solution can be appropriately stored based on storage conditions. As for the working solution for In Vivo experiments, it is recommended to prepare freshly and use it on the same day.
The percentages shown for the solvents indicate their volumetric ratio in the final prepared solution. If precipitation or phase separation occurs during preparation, heat and/or sonication can be used to aid dissolution.

Protocol 1

Add each solvent one by one: 10% DMSO 40% PEG300 5% Tween-80 45% Saline

Solubility: ≥ 2.08 mg/mL (2.68 mM); Clear solution

This protocol yields a clear solution of ≥ 2.08 mg/mL (saturation unknown).

Taking 1 mL working solution as an example, add 100 μL DMSO stock solution (20.8 mg/mL) to 400 μL PEG300, and mix evenly; then add 50 μL Tween-80 and mix evenly; then add 450 μL Saline to adjust the volume to 1 mL.

Protocol 2

Add each solvent one by one: 10% DMSO 90% (20% SBE-β-CD in Saline)

Solubility: ≥ 2.08 mg/mL (2.68 mM); Clear solution

This protocol yields a clear solution of ≥ 2.08 mg/mL (saturation unknown).

Taking 1 mL working solution as an example, add 100 μL DMSO stock solution (20.8 mg/mL) to 900 μL 20% SBE-β-CD in Saline, and mix evenly.

Protocol 3

Add each solvent one by one: 10% DMSO 90% Corn Oil

Solubility: ≥ 2.08 mg/mL (2.68 mM); Clear solution

This protocol yields a clear solution of ≥ 2.08 mg/mL (saturation unknown). If the continuous dosing period exceeds half a month, please choose this protocol carefully.

Taking 1 mL working solution as an example, add 100 μL DMSO stock solution (20.8 mg/mL) to 900 μL Corn oil, and mix evenly.

In Vivo Dissolution Calculator

Please enter the basic information of animal experiments:

Dosage Dosage
mg/kg
Animal Weight (Per Animal) Animal Weight (Per Animal)
g
Dosing Volume (Per Animal) Dosing Volume (Per Animal)
μL
Number of Animals Number of Animals

Recommended: Prepare an additional quantity of animals to account for potential losses during experiments.

Recommended: Prepare an additional quantity of animals to account for potential losses during experiments.

Please enter your animal formula composition:

%
DMSO +

Recommended: Keep the proportion of DMSO in working solution below 2% if your animal is weak.
%
+
+
%
Tween-80 + +
%
Saline +

The co-solvents required include: DMSO, . All of co-solvents are available by MedChemExpress (MCE). , Tween 80. All of co-solvents are available by MedChemExpress (MCE).

Working solution concentration: 0.22 mg/mL

Protocol

Animal Administration^[2]

Rats^[2]
Sprague-Dawley female rats (N=22) are used. Non-pregnant rats are divided into four groups: 1) control, 2) hypothyroidism, 3) hypothyroidism treated with low doses of L-Thyroxine (20 μg/kg/day) and 4) with high doses of L-Thyroxine (100 μg/kg/day). Control rats (group 1) are fed with standard diet, while the intervention rats are fed with iodine-free diet for 12 weeks to induce hypothyroidism (groups 2-4) which is continued for four more weeks to allow screening of hypothyroid status and L-Thyroxine-treatment. Food and water (iodine-free diet) are available ad libitum. The hypothyroid group treated with low (group 3) or high doses of L-Thyroxine (group 4) are injected intraperitoneally every 24 h with respectively 20 μg/kg/day and 100 μg/kg/day. Blood samples are collected for thyroid function screening at week 12 and 16 following the initiation of either the control or iodine-free diet. Hysterectomy is performed under general anesthesia (isoflurane 2%) at the end of the treatment and the two uterine horns are placed in physiological Krebs' solution until isometric tension measurements within no more than 1 h.

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

Purity & Documentation

Select Batch:

Purity: 99.98%

Assay: 99.98%

ee.: 99.98%

Data Sheet (276 KB)
SDS (393 KB)
- English - EN (393 KB)
- Français - FR (393 KB)
- Deutsch - DE (393 KB)
- Norwegian - NO (393 KB)
- Español - ES (393 KB)
- Swedish - SV (393 KB)
- Italian - IT (393 KB)
- Korean - KR (393 KB)
- Portuguese - PT (393 KB)
COA (2659 KB)
Elemental Analysis Report (2659 KB)
HNMR (2659 KB)
CNMR (2659 KB)
RP-HPLC (2659 KB)
NP-HPLC (2659 KB)
MS (2659 KB)
LCMS (2659 KB)
IR (2659 KB)
GC (2659 KB)
OR (2659 KB)
SDS-PAGE (2659 KB)
SEC-HPLC (2659 KB)
Other Report (2659 KB)
Handling Instructions (2659 KB)

References

[1]. Arici M, et al. Association between genetic polymorphism and levothyroxine bioavailability in hypothyroid patients. Endocr J. 2018 Mar 28;65(3):317-323. [Content Brief]

[2]. Corriveau S, et al. Levothyroxine treatment generates an abnormal uterine contractility patterns in an in vitro animalmodel. J Clin Transl Endocrinol. 2015 Sep 9;2(4):144-149. [Content Brief]

Help & FAQs

How should lyophilized recombinant proteins be reconstituted and stored?

1. Before opening the cap, centrifuge the vial at 13000 rpm for 20-30 seconds. This step will ensure that any lyophilized powder that may have adhered to the cap or walls is collected at the bottom of the vial, minimizing the risk of product loss.

Complete Stock Solution Preparation Table

Storage method and period of stock solution: -80°C, 6 months; -20°C, 1 month. When stored at -80°C, please use it within 6 months. When stored at -20°C, please use it within 1 month.

Optional Solvent	Concentration Solvent Mass	1 mg	5 mg	10 mg	25 mg
1M NaOH / DMSO	1 mM	1.2872 mL	6.4361 mL	12.8722 mL	32.1804 mL
1M NaOH / DMSO	5 mM	0.2574 mL	1.2872 mL	2.5744 mL	6.4361 mL
DMSO	10 mM	0.1287 mL	0.6436 mL	1.2872 mL	3.2180 mL
	15 mM	0.0858 mL	0.4291 mL	0.8581 mL	2.1454 mL
	20 mM	0.0644 mL	0.3218 mL	0.6436 mL	1.6090 mL
	25 mM	0.0515 mL	0.2574 mL	0.5149 mL	1.2872 mL
	30 mM	0.0429 mL	0.2145 mL	0.4291 mL	1.0727 mL
	40 mM	0.0322 mL	0.1609 mL	0.3218 mL	0.8045 mL
	50 mM	0.0257 mL	0.1287 mL	0.2574 mL	0.6436 mL
	60 mM	0.0215 mL	0.1073 mL	0.2145 mL	0.5363 mL
	80 mM	0.0161 mL	0.0805 mL	0.1609 mL	0.4023 mL
	100 mM	0.0129 mL	0.0644 mL	0.1287 mL	0.3218 mL

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L-Thyroxine

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Publications Citing Use of MedChemExpress (MCE) L-Thyroxine

All Endogenous Metabolite Isoforms

Biological Activity

Chemical Information

Publications (13)

Solvent & Solubility

Protocol

Purity & Documentation

References

Help & FAQs

Complete Stock Solution Preparation Table

L-Thyroxine Related Classifications

Cat. No.: HY-18341