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Thyroid Strength

MegaFood
4.5
★ ★ ★ ★ ★
(939 ratings)
Ashwagandha 250 mg
Tyrosine 300 mg
Selenium 70 mcg
Kelp 125 mg
Product Image
Score65

Strong ashwagandha and a coherent thyroid-support blend are overshadowed by an implausible iodine unit that must be verified before use.

How scoring works
Quantity:90 Tablet(s) • (45 servings)
Goals:
General Health
Immunity

Score 65

Strong ashwagandha and a coherent thyroid-support blend are overshadowed by an implausible iodine unit that must be verified before use.

How scoring works
$44.99($0.99 per serving)
iHerb
$ 44.99
Amazon
$ 44.99
Vitacost
$ 44.99
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Analysis

Sensoril ashwagandha is a standardized extract at a meaningful amount, while tyrosine, selenium, and zinc add relevant thyroid and stress-response nutrients. Holy basil, coleus, and kelp broaden the formula without hiding the main active amounts.

The product is much more targeted than a general multivitamin and fits only a defined thyroid-support use case. It does not provide broad immune coverage, and the serving cost is high for routine supplementation.

The supplied data show iodine in milligrams rather than the microgram-scale amount normally used in supplements. That may be a unit error, but the consequence would be serious if accurate, so the physical package label must be checked and the product should not be used until the discrepancy is resolved.

Who is it for
  • Adults whose package label confirms a safe iodine amount
  • People seeking standardized ashwagandha with tyrosine
  • Users working with a clinician on thyroid support
Best for
  • Targeted thyroid-nutrient support
  • Stress support within a thyroid-focused plan
  • Standardized ashwagandha use

Pros

  • Standardized Sensoril ashwagandha
  • Clearly quantified L-tyrosine
  • Selenium and zinc included
  • Focused thyroid-oriented formula

Cons

  • Iodine unit is implausible in the supplied record
  • High serving cost
  • Narrow fit outside thyroid support
  • Inactive ingredients are incomplete

Warnings

  • Do not use until the iodine amount and unit have been verified on the physical package label.
  • If the listed milligram-scale iodine amount were accurate, it could pose a serious thyroid and safety risk requiring medical evaluation.
  • Ashwagandha, coleus, tyrosine, and iodine can complicate thyroid disease or thyroid-medication management.

Nutrient quality

60 Moderate impact

The targeted blend uses strong forms for selenium and ashwagandha with useful thyroid-oriented support. The supplied iodine unit indicates a potentially dangerous amount and overwhelms the otherwise reasonable formulation.

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Ingredient transparency

81 Highest impact

Active amounts and most forms are clearly stated without a hidden blend. The questionable iodine unit, missing directions, and absent excipient list require label verification.

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Customer satisfaction

69 High impact

The favorable aggregate rating is backed by a large review count. No specific feedback is supplied to assess repeated problems, tablet experience, or whether use matches the thyroid-support purpose.

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Value for money

44 Lower impact

Standardized ashwagandha and food-form minerals add quality, but the unresolved iodine amount makes the formula difficult to justify. The relatively costly serving also compares poorly with safer, unambiguous alternatives.

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Goals

General Health
General Health
Impact
High effect
B- Goal FitC+ Strength of SupportC+ CoverageB- Formula Quality
Selenium · 70 mcgAshwagandha · 250 mgZinc · 8 mg

Standardized ashwagandha, selenium, zinc, and tyrosine create a targeted formula for stress response and thyroid-related nutrient support. The pathway is coherent for a defined use case but less broadly applicable than a balanced multivitamin.

The supplied label lists iodine at an unusually large unit, so that amount should be verified before use because excessive iodine can disrupt thyroid function. Ashwagandha, coleus, and tyrosine also make this a poor casual choice for people with thyroid disorders or thyroid medication without individualized guidance.

Study evidence
Ashwagandha Supportive 31 studies
Selenium Supportive 70 studies
Zinc Supportive 60 studies
Immunity
Immunity
Impact
Moderate effect
C Goal FitC- Strength of SupportC- CoverageC+ Formula Quality
Zinc · 8 mgSelenium · 70 mcg

Selenium and zinc offer limited immune overlap, but the formula is designed primarily for thyroid support. Ashwagandha is standardized, while the remaining botanicals are directed more toward thyroid and stress pathways than immunity.

The supplied data list an iodine amount that is extraordinarily high and may be a unit error, so the package label must be verified before use. If that iodine amount is accurate, it would present a serious thyroid and safety concern and the product should not be used without medical evaluation.

Study evidence
Selenium Mixed 37 studies
Zinc Supportive 73 studies

Ingredients

IngredientAmount per serving
Iodine (Saccharomyces cerevisiae)
 150 mg
Zinc (Saccharomyces cerevisiae)
 8 mg
Selenium (Saccharomyces cerevisiae)
 70 mcg
Copper (S. cerevisiae)
 0.35 mg
L-Tyrosine
300 mg
Holy Basil leaf extract
250 mg
Sensoril Ashwagandha root & leaf extract (Withanolides)
 250 mg
Coleus forskohlii Root Extract
150 mg
organic Kelp
125 mg
Gluten Free Adults 18–50 Kosher Dairy Free Vegetarian
Report overview
Ashwagandha (Withanolides) · 250 mg OverallScore84
A- Active Ingredient Quality & BioavailabilityA+ Dose, Safety & Label TransparencyD+ Value

MegaFood Thyroid Strength provides 250 mg of Sensoril ashwagandha root-and-leaf extract and has 932 reviews averaging 4.52. Its form, dose, delivery, transparency, and $0.99 per-serving price were evaluated directly against the collection rubric.

View ingredientView products
Tyrosine · 300 mg OverallScore68
A Active Ingredient Quality & BioavailabilityB- Dose, Safety & Label TransparencyF Value

Thyroid Strength supplies 300 mg of clearly disclosed L-Tyrosine, earning preferred-form credit but a dosage score of 60. Customer feedback averages 4.52 across 932 reviews; people using thyroid medication or managing a thyroid condition should review the iodine, botanicals, and tyrosine combination with a clinician.

View ingredientView products
Selenium (Saccharomyces cerevisiae) · 70 mcg OverallScore65
B+ Active Ingredient Quality & BioavailabilityB Dose, Safety & Label TransparencyF Value

Selenium yeast supplies organic selenium in a food-form matrix. The 70 mcg serving provides useful selenium but falls below the preferred maintenance range. The standardized cost per target selenium amount is very high.

View ingredientView products
Loading alternative details
74 Performance

Thyroid Support Complex

Pure Encapsulations
<p>Tyrosine, standardized ashwagandha, iodine, selenium, zinc, and thyroid-focused botanicals create a more coherent and better-specified formula. Substantial selenium and zinc narrow its role to defined needs, and thyroid-active ingredients require condition-specific guidance.</p>
68 Performance

Thyro-T

LifeSeasons
<p>Standardized ashwagandha, iodine, selenium, and tyrosine provide a clearer thyroid-support base than the original label with its questionable iodine unit. Bovine thyroid tissue and several hormone-active botanicals complicate routine use and call for medical supervision.</p>
68 Performance

Triple Action Thyroid

Life Extension
<p>Methylcobalamin, tyrosine, fermented ginseng, and branded ashwagandha offer useful energy and stress support without relying on the original product's questionable iodine entry. Repeated iodine and ashwagandha listings still create label uncertainty, and the thyroid-active blend requires caution.</p>
80 Budget

Thyroid Health Formula

Natural Factors
<p>Meaningful tyrosine and well-chosen mineral forms retain thyroid support at a much lower serving cost. Ashwagandha and guggul lack full standardization details, and the combination should be reviewed with a clinician when thyroid disease or medication is involved.</p>
77 Budget

Essential Thyroid Nutrition

NutriCology
<p>Iodine, zinc, selenium, vitamin B12, tyrosine, and ashwagandha provide a focused alternative at a lower serving cost. Botanical standardization is incomplete, while iodine, ashwagandha, and forskolin may affect thyroid management.</p>
47 Budget

Thyroid Support Liquid Phyto-Caps

Gaia Herbs Professional Solutions
<p>Tyrosine, iodine, and ashwagandha preserve the central thyroid concept at a lower serving cost. Two proprietary blends hide most ingredients and doses, making potency and safety much harder to judge.</p>
81 Value

ThyroSense

Natural Factors WS WomenSense
<p>A meaningful tyrosine amount and well-chosen mineral forms provide strong thyroid relevance with favorable serving value. Ashwagandha and guggul are not fully standardized, and thyroid conditions or medicines warrant clinician review.</p>
80 Value

Thyrocsin

Thorne
<p>High-quality iodine, selenium, and tyrosine forms create a compact formula with a long supply and better value balance. Ashwagandha is modest, while iodine and ashwagandha may affect thyroid management.</p>
72 Value

Thyroid Support Complex

Pure Encapsulations
<p>Strong mineral forms and meaningful tyrosine and ashwagandha provide broad thyroid coverage with a more credible label than the original. The serving cost is higher than some options, but ingredient depth supports the value for a defined need.</p>
Report alternatives

Sources

Published studies used for the product analysis and the top-ranked studies for each ingredient and goal.

  1. A randomized, double blind, placebo controlled study to evaluate the effects of ashwagandha (Withania somnifera) extract on sleep quality in healthy adults.
    Deshpande A; Irani N; Balkrishnan R; Benny IR · Sleep medicine · 2021
    Randomized trial150 participantsGeneral Health forAshwagandha
  2. Effects of Ashwagandha ( Withania somnifera) standardized root extract on physical endurance and VO 2max in healthy adults performing resistance training: An eight-week, prospective, randomized, double-blind, placebo-controlled study.
    Verma N; Gupta SK; Patil S; Tiwari S; Mishra AK · F1000Research · 2024
    Randomized trial80 participantsGeneral Health forAshwagandha
  3. Efficacy of Ashwagandha (Withania somnifera [L.] Dunal) in improving cardiorespiratory endurance in healthy athletic adults.
    Choudhary B; Shetty A; Langade DG · Ayu · 2016
    Randomized trial50 participantsGeneral Health forAshwagandha
  4. Withania somnifera (L.) Dunal as Add-On Therapy for COPD Patients: A Randomized, Placebo-Controlled, Double-Blind Study.
    Singh P; Salman KA; Shameem M; Warsi MS · Frontiers in pharmacology · 2022
    Randomized trial150 participantsGeneral Health forAshwagandha
  5. Effect of Ashwagandha (Withania somnifera) extract on sleep: A systematic review and meta-analysis.
    Cheah KL; Norhayati MN; Husniati Yaacob L; Abdul Rahman R · PloS one · 2021
    Meta-analysis400 participants5 studies pooledGeneral Health forAshwagandha
  6. Associations of selenium status with all-cause and cause-specific mortality: a systematic review and meta-analysis of cohort studies.
    Cui Z; Xie R; Lu X; Schomburg L; Brenner H; Schöttker B · Redox biology · 2025
    Meta-analysis95 participants20 studies pooledGeneral Health forSelenium
  7. Dietary Antioxidants, Circulating Antioxidant Concentrations, Total Antioxidant Capacity, and Risk of All-Cause Mortality: A Systematic Review and Dose-Response Meta-Analysis of Prospective Observational Studies.
    Jayedi A; Rashidy-Pour A; Parohan M; Zargar MS; Shab-Bidar S · Advances in nutrition (Bethesda, Md.) · 2019
    Meta-analysis507,251 participants41 studies pooledGeneral Health forSelenium
  8. The efficacy and safety of selenium supplementation versus placebo in the treatment of Graves' orbitopathy: A systematic review and meta-analysis of randomised controlled trials.
    Sharabati I; Qafesha RM; Hindawi MD; Amro S; Ayesh BM · Clinical endocrinology · 2024
    Meta-analysis4 studies pooledGeneral Health forSelenium
  9. Associations of plasma metal concentrations with the risks of all-cause and cardiovascular disease mortality in Chinese adults.
    Shi L; Yuan Y; Xiao Y; Long P; Li W; Yu Y; Liu Y; Liu K; Wang H; Zhou L; Yang H; Li X; He M; Wu T · Environment international · 2021
    Cohort study6,155 participantsGeneral Health forSelenium
  10. Updates on clinical studies of selenium supplementation in radiotherapy.
    Puspitasari IM; Abdulah R; Yamazaki C; Kameo S; Nakano T; Koyama H · Radiation oncology (London, England) · 2015
    Systematic review16 studies pooledGeneral Health forSelenium
  11. Effectiveness of sodium bicarbonate and zinc chloride mouthwashes in the treatment of oral mucositis and quality of life in patients with cancer under chemotherapy.
    Mohammadi F; Oshvandi K; Kamallan SR; Khazaei S; Ranjbar H; Ahmadi-Motamayel F; Gillespie M; Jenabi E; Vafaei SY · Nursing open · 2022
    Randomized trial144 participantsGeneral Health forZinc
  12. Zinc supplementation in young children with acute diarrhea in India.
    Sazawal S; Black RE; Bhan MK; Bhandari N; Sinha A; Jalla S · The New England journal of medicine · 1995
    Randomized trial937 participantsGeneral Health forZinc
  13. Associations of mortality with ocular disorders and an intervention of high-dose antioxidants and zinc in the Age-Related Eye Disease Study: AREDS Report No. 13.
    Clemons TE; Kurinij N; Sperduto RD; AREDS Research Group · Archives of ophthalmology (Chicago, Ill. : 1960) · 2004
    Randomized trial4,753 participantsGeneral Health forZinc
  14. Effects of zinc and probiotic co-supplementation on inflammation, gastrointestinal symptoms, quality of life, and mood in irritable bowel syndrome patients.
    Rezazadegan M; Soheilipour M; Amani R · Scientific reports · 2026
    Randomized trial84 participantsGeneral Health forZinc
  15. Effect of zinc sulfate supplementation on premenstrual syndrome and health-related quality of life: Clinical randomized controlled trial.
    Siahbazi S; Behboudi-Gandevani S; Moghaddam-Banaem L; Montazeri A · The journal of obstetrics and gynaecology research · 2018
    Randomized trial142 participantsGeneral Health forZinc
  16. Effects of selenium supplementation on selenoprotein gene expression and response to influenza vaccine challenge: a randomised controlled trial.
    Goldson AJ; Fairweather-Tait SJ; Armah CN; Bao Y; Broadley MR; Dainty JR; Furniss C; Hart DJ; Teucher B; Hurst R · PloS one · 2011
    Randomized trial119 participantsImmunity forSelenium
  17. Effect of selenium on immune response against hepatitis B vaccine with accelerated method in insulin-dependent diabetes mellitus patients.
    Janbakhsh A; Mansouri F; Vaziri S; Sayad B; Afsharian M; Rahimi M; Shahebrahimi K; Salari F · Caspian journal of internal medicine · 2013
    Randomized trial62 participantsImmunity forSelenium
  18. Chemoprevention trial of human hepatitis with selenium supplementation in China.
    Yu SY; Li WG; Zhu YJ; Yu WP; Hou C · Biological trace element research · 1990
    Non-randomized trial20,847 participantsImmunity forSelenium
  19. Selenium nanoparticles as adjunctive therapy in sepsis: A pilot randomized clinical trial.
    Gu WJ; Huang W; Zhao FZ; Yuan XK; Jin K; Chen JL; Zhang CY; Huang Y; He L; Zhuang H; Yin HY; Chen T · Drug resistance updates : reviews and commentaries in antimicrobial and anticancer chemotherapy · 2026
    Randomized trial70 participantsImmunity forSelenium
  20. Selenium supplementation in patients with autoimmune thyroiditis decreases thyroid peroxidase antibodies concentrations.
    Gärtner R; Gasnier BC; Dietrich JW; Krebs B; Angstwurm MW · The Journal of clinical endocrinology and metabolism · 2002
    Randomized trial70 participantsImmunity forSelenium
  21. Nutrient supplementation for prevention of viral respiratory tract infections in healthy subjects: A systematic review and meta-analysis.
    Vlieg-Boerstra B; de Jong N; Meyer R; Agostoni C; De Cosmi V; Grimshaw K; Milani GP; Muraro A; Oude Elberink H; Pali-Schöll I; Roduit C; Sasaki M; Skypala I; Sokolowska M; van Splunter M; Untersmayr E; Venter C; O'Mahony L; Nwaru BI · Allergy · 2022
    Meta-analysis199,055 participants115 studies pooledImmunity forZinc
  22. Zinc supplementation reduces the incidence of acute lower respiratory infections in infants and preschool children: a double-blind, controlled trial.
    Sazawal S; Black RE; Jalla S; Mazumdar S; Sinha A; Bhan MK · Pediatrics · 1998
    Randomized trial609 participantsImmunity forZinc
  23. A randomized controlled trial of zinc supplementation in the treatment of acute respiratory tract infection in Thai children.
    Rerksuppaphol S; Rerksuppaphol L · Pediatric reports · 2020
    Randomized trial64 participantsImmunity forZinc
  24. The effect of zinc and vitamin A supplementation on immune response in an older population.
    Fortes C; Forastiere F; Agabiti N; Fano V; Pacifici R; Virgili F; Piras G; Guidi L; Bartoloni C; Tricerri A; Zuccaro P; Ebrahim S; Perucci CA · Journal of the American Geriatrics Society · 1998
    Randomized trial136 participantsImmunity forZinc
  25. The role of specific nutrients in preventing immune system and blood cell disorders: an umbrella review.
    Vecchietti A; Strano P; Minutolo G; Grieco V; Cappuccio G; Granvillano G; Confalonieri L; Briganti GL; Raso E; Chimienti M; Pellegrini M; Mercogliano M; Spatari G; Lugli C; Urbano T; Lorenzon A · Journal of preventive medicine and hygiene · 2026
    Systematic review13 studies pooledImmunity forZinc