Blackstone Labs Letro XT supports hormonal balance and equilibrium following aggressive supplement cycles — the outside of your body may look fantastic after an intense training and prohormone cycle, but intense training brings massive disruption to the body's homeostatic environment on the inside. Letro XT can be used on-cycle or off-cycle to help support natural testosterone production, limit water retention, and reduce other side effects that accompany the use of hardcore muscle-building supplements. The formula centers on two related aromatase-modulating compounds: 3β-Hydroxy-Androsta-1,4,6-Triene-17-One, reported to help reduce estrogen biosynthesis while supporting natural production of DHT and testosterone (encouraging fat loss and muscle building), and 3β-Hydroxy-Androsta-4,6-Diene-17-One, an ATD metabolite that helps limit the conversion of testosterone into estrogen while promoting androgenic effects that support greater gains in muscle and strength. Take 1 tablet in the morning and 1 tablet in the evening. Do not exceed 4 tablets in any 24-hour period. Not for use by persons under 18. Not for women.†
Supplement Facts — Blackstone Labs Letro XT (Per 1 Tablet)
3β-Hydroxy-Androsta-1,4,6-Triene-17-One — reduces estrogen biosynthesis, supports natural DHT and testosterone production
3β-Hydroxy-Androsta-4,6-Diene-17-One — ATD metabolite, limits testosterone-to-estrogen conversion, promotes androgenic effects
Other Ingredients: Microcrystalline Cellulose, Phosphatidylcholine 75%, Hydroxypropyl Beta Cyclodextrin, Medium Chain Triglycerides, Phytosterols, Magnesium Stearate, Silica
Individual ingredient doses not published in available label sources — confirm exact amounts on your current bottle
Take 1 tablet in the morning and 1 tablet in the evening
Do not exceed 4 tablets in any 24-hour period
Can be used on-cycle or off-cycle (as PCT)
Not for use by persons under 18 years of age
Not recommended for women — supports increased testosterone production
Manufactured in a facility that processes milk, eggs, shellfish, tree nuts, peanuts, wheat, soybeans, and sesame (no major allergens intentionally included)
May cause a positive drug test
California Prop 65 Warning applies.
Why Estrogen Ratio Matters More Than Testosterone Alone When a Cycle Ends
Your body needs balance — that's why things work in ratio, like estrogen and testosterone. When your prohormone cycle ends, your natural testosterone levels are typically low (suppressed by the cycle's exogenous hormonal signals), but your estrogen levels remain at your natural baseline range — meaning comparatively, your estrogen is at a much higher ratio relative to testosterone than it should be. This is where Letro XT specifically targets its two-compound approach: rather than just boosting testosterone in isolation, it works simultaneously to increase natural testosterone production while suppressing estrogen levels, restoring the ratio balance that governs how effectively your body can use whatever testosterone it does have.†
3β-Hydroxy-Androsta-1,4,6-Triene-17-One — Dual Estrogen and Androgen Action
This compound is reported to help reduce estrogen biosynthesis — targeting the production side of the estrogen equation directly — while simultaneously supporting the natural production of both DHT and testosterone. This dual mechanism encourages fat loss and muscle building through two complementary pathways: lower estrogen production reduces water retention and estrogen-related side effects, while elevated androgen production supports the anabolic drive needed to actually build and maintain muscle during the recovery window.†
3β-Hydroxy-Androsta-4,6-Diene-17-One — Blocking the Conversion Pathway
This second compound is a metabolite of ATD (androsta-3,5-diene-7,17-dione, better known as Arimistane) that helps limit the conversion of testosterone into estrogen specifically at the aromatization step, while also promoting androgenic effects that support greater gains in muscle and strength. Working alongside the first compound's dual-action mechanism, this provides an additional layer of protection against the aromatase-driven estrogen conversion that can undermine post-cycle testosterone recovery.†
On-Cycle or Off-Cycle — Genuine Flexibility
Unlike products positioned exclusively as PCT, Letro XT can be used both on and off cycle to help support natural testosterone production, limit water retention, and manage other side effects accompanying hardcore supplement usage. This means Letro XT can be run alongside an active prohormone cycle to manage estrogen-related side effects in real time, or used in the traditional PCT window after a cycle ends to restore natural hormone balance — genuine versatility that reflects the underlying mechanism working on both estrogen suppression and testosterone support simultaneously, regardless of what else is (or isn't) happening hormonally at the time.†
Frequently Asked Questions
Is Letro XT a PCT, a test booster, or both?
Both — Letro XT works as a PCT and a test booster simultaneously. A proper PCT assists in restoring testosterone production to natural levels while controlling estrogen; Letro XT is specifically designed to provide both of these benefits in a single product.†Can Letro XT be used without running a prohormone cycle first?
Yes — Letro XT can be used on or off cycle. It's appropriate as a standalone estrogen-management and testosterone-support product, not exclusively as post-cycle recovery.†How does Letro XT compare to Hi-Tech Novedex XT?
The two products share the same first two active compounds (3β-Hydroxy-Androsta-1,4,6-Triene-17-One and 3β-Hydroxy-Androsta-4,6-Diene-17-One). Novedex XT additionally includes Arimistane as a third compound in its blend; Letro XT's confirmed formula centers on just the two shared compounds.†Will Letro XT cause a positive drug test?
Likely yes — these androsta-based steroidal compounds are generally prohibited by WADA and NCAA as androgen metabolites. Tested athletes should not use this product.†
How to Take Blackstone Labs Letro XT
Take 1 tablet in the morning and 1 tablet in the evening. Do not exceed 4 tablets in any 24-hour period. Can be used on-cycle for real-time estrogen management, or off-cycle as PCT to restore hormonal balance. Not for use by persons under 18. Do not use if you are currently breastfeeding, pregnant, or planning to become pregnant. Consult your doctor prior to use if you have any medical conditions (including kidney or liver disease) or are taking any prescription or over-the-counter medications. Discontinue use two weeks prior to surgery. Do not exceed recommended dosage or take with alcohol. Do not take if dehydrated or in conditions of excessive heat. Discontinue use immediately if you experience rapid heartbeat, dizziness, vomiting, difficulty breathing, chest pain, or other similar symptoms and consult your healthcare professional. California Prop 65 Warning applies.†
Why Buy at Get Yok'd
Real-time inventory across all five Southern California stores
Available in Burbank, Glendale, Glendale Galleria, Pasadena, and North Hollywood
Authorized Blackstone Labs retailer — carrying Letro XT alongside PCT V, Eradicate, and the full Blackstone Labs hormone-support lineup
Staff who can help you determine whether Letro XT fits your cycle plan on-cycle or as PCT
One of the best loyalty programs in the supplement industry — earn rewards on every purchase
Who Should Not Take Letro XT
Not for use by persons under 18 years of age
Not recommended for women — designed to increase testosterone production
Do not use if breastfeeding, pregnant, or planning to become pregnant
Not for tested athletes — androsta-based steroidal compounds are prohibited by WADA and NCAA
Not for individuals with kidney or liver disease without physician clearance
Discontinue use two weeks prior to surgery
Do not take with alcohol
Do not take if dehydrated or in conditions of excessive heat
Discontinue use immediately and consult a healthcare professional if you experience rapid heartbeat, dizziness, vomiting, difficulty breathing, chest pain, or other adverse symptoms
Consult a physician before use if taking any prescription medications or having any medical condition
Do not exceed recommended dosage
California Prop 65 Warning applies.
Keep out of reach of children.
†These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.