By Robert Schinetsky

Testosterone is the hormone most synonymous with men. It’s what helps them to build muscle, stay lean, perform better, recover faster, and live a healthier life. However, beginning around age 30, natural testosterone production declines ~1% annually.

Declining testosterone levels negatively impact cognitive function, mood, body composition, sex drive, athletic performance, and cardiovascular health.

Hormone therapy and pharmaceuticals have been around for some time. While they are effective for boosting testosterone, they are not without their drawbacks and side effects. As a result, researchers and everyday men have been in search of natural alternatives that support aging men across their lifespan.

Several years back, Advanced Molecular Labs released the leading research-backed natural male enhancement formula in AML Test. This was followed up by the highly coveted Sex Cocktail.

But, like most men, we’re never satisfied, and so our search continued for additional options that could further naturally support testosterone levels (and with it overall men’s health).

That unrelenting quest led to the discovery of a little known compound called D-chiro-inositol (DCI).

What is Inositol?

Inositol is a sugar alcohol (polyol) naturally synthesized by the body, and it can be found in food. It was considered a relative of the B-vitamin family, and it is involved in a wide variety of biological processes, including cell signaling, mRNA transcription, insulin signaling, bone formation, stress response and embryo development.[1]

The kidney is the primary inositol-synthesizing organ, generating ~2-4g of myo-inositol per day, while the liver and brain make significantly less. Inositol can also be obtained through the diet, and the average dietary intake is 0.5–1.0 g/day from a variety of cereals, legumes, nuts, and seeds, primarily.[2]

Not only is myo-inositol involved in more actions than DCI in the body, it is also DCI’s precursor. D-chiro-inositol is synthesized from myo-inositol by a member of the epimerase enzyme family during metabolic stress, in response to increased insulin release.

This is a tightly regulated process in the body, and an excessive increase or decrease in epimerase enzymatic activity can lead to inositol imbalance, which alters the response of a given tissue to external stimuli.

For example, insulin resistance impairs the conversion of myo-inositol to DCI in muscles, fat and liver.[3]

In addition to being synthesized within the body, DCI can also be obtained from various plants where it’s found as 3-O-methyl-D-chiro-inositol (aka pinitol). Plants rich in DCI include, soybeans, kudzu, and various clovers.[4]

D-Chiro-Inositol vs Myo-Inositol

Myo-inositol and D-chiro-inositol are the most abundant isomers of inositol, though myo-Inositol represents roughly 99% of the mammalian inositol pool. Myo-inositol levels are higher in tissues that use large amounts of glucose, such as the brain and heart. D-chiro-inositol (DCI) is higher in tissues requiring glucose storage, such as the liver and skeletal muscles, as well as androgen production.[3,5,6]

D-chiro-inositol mediates different functions than those of myo-inositol. For instance, D-chiro Inositol is a strong modulator of steroidogenesis, suggesting that it may be more applicable to different situations than myo-inositol.[7] Specifically, DCI is regulates various steroidogenic enzymes, including 17α-hydroxylase, 3β-hydroxysteroid dehydrogenase, and aromatase.[8] DCI also functions as a second messenger of insulin, which stimulates testosterone synthesis in Leydig cells.[9,10]

Myo-inositol, on the other hand, is involved in the Follicle Stimulating Hormone (FSH) and the Thyroid Stimulating Hormone (TSH) pathways.

A recently published text entitled Guide to Inositols stated that “d-chiro-inositol inhibits the expression of the aromatase enzyme, leading to a reduced conversion of androgens into estrogens. Myo-inositol is thus useful to restore correct spermatogenesis, while d-chiro-inositol could represent a useful molecule in the case of reduced testosterone.”[7]

In other words, for improving anabolic signaling look to d-chiro-inositol, and for healthy sperm consider myo-inositol.

DCI the Man-Making Supplement

All too often in the realm of dietary supplements, the mechanistic data is promising, but when put into action in human clinical trials (e.g. consuming supplements orally in a research study), the results fail to measure up to the hype.

DCI is one of those rare ingredients whose real world results deliver where it counts!

A landmark 2021 pilot study gave male volunteers (average age: 37 years) 500mg d-chiro-inositol twice daily (1 g/day) for 30 days. At the end of the trial, DCI supplementation led to a dramatic reduction in both estrone (-85%) and 17β-estradiol levels (−14.4%), while increasing testosterone (+23.4%), dehydroepiandrosterone (+13.8%) and epiandrosterone (+39%)![11]

While these results suggest that DCI seemingly promotes androgen synthesis, it actually inhibits androgen catabolism rather than aiding its biosynthesis via aromatase inhibition.

Based on these findings, researchers have concluded that “D-chiro-Ins could exert appreciable anti-estrogenic activity in the treatment of male and female clinical states that would benefit from androgen increase and/or estrogen decrease.”[12]

A separate pilot study, also conducted in 2021, this time in older hypogonadal men (average age ~69 years old), consumed 600mg of DCI twice per day (1200mg, daily total) for 30 days.[13]

At the end of the month-long study, men receiving the 1,200mg d-chiro-inositol supplement demonstrated increased serum testosterone and androstenedione, and reduced oestradiol and oestrone.[13] Researchers also documented improvements in glycaemia and insulin resistance as well as induced statistically significant reduction of waist circumference, body mass index (BMI), and weight.^†

How to Use DCI Test Booster

Consume one capsule of AML DCI Testosterone Booster two times daily on an empty stomach. Do NOT consume more than two capsules per day.^†

AML DCI Test Booster is intended for men only.

Can I Stack DCI Test Booster with AML Test?

YES!

DCI Test Booster can be stacked with AML Test for increased male enhancement support.^†

Takeaway

Inositol is a vital signaling molecule in the body. D-chiro-inositol (DCI) is one of the two prominent inositol isomers in the body that impacts insulin signaling, energy utilization, and male hormone levels.

While inositol can be obtained from the diet, human studies have shown that DCI is safe and beneficial when consumed between 1000-1200mg per day.

AML DCI Test Booster supplies a premium 1,200mg per day. It can be used by itself and stacked with AML Test or AML Sex Cocktail to support natural testosterone levels, sexual health, performance, mood, and recovery.^†

^{† 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.}

^{© Published by Advanced Research Media, Inc. 2024
© Reprinted with permission from Advanced Research Media, Inc.}

References

1. Kiani AK, Paolacci S, Calogero AE, Cannarella R, Di Renzo GC, Gerli S, Della Morte C, Busetto GM, De Berardinis E, Del Giudice F, Stuppia L, Facchinetti F, Dinicola S, Bertelli M. From Myo-inositol to D-chiro-inositol molecular pathways. Eur Rev Med Pharmacol Sci. 2021 Mar;25(5):2390-2402. doi: 10.26355/eurrev_202103_25279. PMID: 33755975.
2. Corrado F, Santamaria A. Chapter 19 - Myoinositol Supplementation on Insulin Resistance in Gestational Diabetes. In: Watson RR, Dokken BB, eds. Glucose intake and utilization in pre-diabetes and diabetes. Boston: Academic Press, 2015: 229–34
3. Larner J. D-chiro-inositol--its functional role in insulin action and its deficit in insulin resistance. Int J Exp Diabetes Res. 2002;3(1):47-60. doi: 10.1080/15604280212528. PMID: 11900279; PMCID: PMC2478565.
4. Negishi O, Mun’im A, Negishi Y. Content of methylated inositols in familiar edible plants. J Agric Food Chem 2015; 63: 2683-2688
5. DiNicolantonio JJ, H O'Keefe J. Myo-inositol for insulin resistance, metabolic syndrome, polycystic ovary syndrome and gestational diabetes. Open Heart. 2022 Mar;9(1):e001989. doi: 10.1136/openhrt-2022-001989. PMID: 35236761; PMCID: PMC8896029.
6. Croze M.L., Soulage C.O. Potential role and therapeutic interests of myo-inositol in metabolic diseases. Biochimie. 2013;95:1811– doi: 10.1016/j.biochi.2013.05.011.
7. Stringaro, A., Nordio, M., & Vazquez-Levin, M. (2023). Chapter 13 - Application of myo-inositol and d-chiro-inositol in andrological issues (V. Unfer & D. B. T.-A. C. G. to I. Dewailly (eds.); pp. 197–211). Academic Press. https://doi.org/https://doi.org/10.1016/B978-0-323-91673-8.00012-1
8. Gambioli R, Montanino Oliva M, Nordio M, Chiefari A, Puliani G, Unfer V. New Insights into the Activities of D-Chiro-Inositol: A Narrative Review. Biomedicines. 2021 Oct 2;9(10):1378. doi: 10.3390/biomedicines9101378. PMID: 34680494; PMCID: PMC8533370.
9. Leisegang K, Henkel R. The in vitro modulation of steroidogenesis by inflammatory cytokines and insulin in TM3 Leydig cells. Reprod Biol Endocrinol. 2018;16:26. doi: 10.1186/s12958-018-0341-2.
10. Pitteloud N, Hardin M, Dwyer AA, Valassi E, Yialamas M, Elahi D, et al. Increasing insulin resistance is associated with a decrease in Leydig cell testosterone secretion in men. J Clin Endocrinol Metab. 2005;90:2636–41. doi: 10.1210/jc.2004-2190.
11. Monastra G., Vazquez-Levin M., Bezerra Espinola M.S., Bilotta G., Laganà A.S., Unfer V. D-chiro-inositol, an aromatase down-modulator, increases androgens and reduces estrogens in male volunteers: A pilot study. Basic Clin. Androl. 2021;31:1–17. doi: 10.1186/s12610-021-00131-x.
12. Gambioli R., Forte G., Aragona C., Bevilacqua A., Bizzarri M., Unfer V. The use of D-chiro-Inositol in clinical practice. Eur. Rev. Med. Pharmacol. Sci. 2021;25:438–446. doi: 10.26355/eurrev_202101_24412.
13. Nordio M, Kumanov P, Chiefari A, Puliani G. D-Chiro-Inositol improves testosterone levels in older hypogonadal men with low-normal testosterone: a pilot study. Basic Clin Androl. 2021 Nov 12;31(1):28. doi: 10.1186/s12610-021-00146-4. PMID: 34763665; PMCID: PMC8588714.
14. Bevilacqua A, Bizzarri M. Inositols in insulin signaling and glucose metabolism. Int J Endocrinol 2018;2018:1968450 10.1155/2018/1968450