Is anyone drinking Soylent 2.0 tracking their testosterone / estrogen levels?


I have recently heard that the isoflavones in soy may lower my testosterone (and increase my estrogen). Rather than rely on studies in rats and in people consuming far lower quantities, both of which may have no bearing on my experience, I am interested in finding hard data from people using high quantities (60%+) of Soylent 2.0 in their diet for extended periods of time (3 months+).

First a little background information, so you know I already understand the negative hype around soy is WAY overblown, and perhaps even doing harm by leading people away from a very healthy substance.

This post from the University of Maryland Medical Center clearly states that soy protein has many more benefits than drawbacks.

This post on, which claims to summarize 12 different studies on the consumption of soy isoflavones, also states, “They appear to be healthy, and are not anathema to young men and Testosterone levels.”

This article written in the Center For Science In The Public Interest’s Nutrition Action Health Letter discusses many of the negative claims made against Soy - including the claim that it reduces a man’s masculinity by decreasing testosterone and increasing estrogen. Thankfully, on those points, they conclude soy protein in normal doses is not likely to turn me from a he into a she.

One thing did catch my eye in that Nutrition Action Health Letter article though. They mention a patient in Texas that supposedly set off this whole Soy-Estrogen mania when his boobs started to ache and his libido waned after drinking 3 quarts of soy milk a day containing 360 mg of isoflavones. Apparently his estrogen levels were 8x higher than normal while drinking that much soy protein, but they supposedly then dropped back to normal levels after he stopped drinking the soy milk.

This gave me pause because I’ve been living on 80% to 100% Soylent 2.0 for 4 months now. This means I am consuming between 208 and 260 mg per day of isoflavones. So far, my libido remains strong and my breasts aren’t sore. Still seems like a lot…

Anyway, the reason for the very specific title of this post was to avoid a huge debate on whether soy protein and the isoflavones therein does or does not cause a decrease in testosterone. While any useful information regarding this topic is welcomed, I am more concerned with finding people who are tracking testosterone levels (and estrogen too for that matter) over time while on Soylent.

I am drawing blood again next week and have added these tests to my panel. I’ll keep people posted over time, but would like to have others do the same. It will help if you can post the actual test results with identifiable information redacted, so we know that you’re not just winding us up…

Thanks for your assistance. I hope we can cobble together something interesting here.

Studies Showing Adverse Effects of Dietary Soy, 1939-2014 :skull_crossbones:

Thanks for doing this. I can’t afford to drink enough 2.0 to contribute, but I like the idea. Are you testing both testosterone and estrogen, or just testosterone?

It would be interesting to see results from both men and women


I agree. Results from men and women would be good, and yes, I plan to test estrogen too. Really wish I had a pre-Soylent baseline though.

I recognize this data will be far from conclusive as there are so many other variables that could impact those levels - especially if my testosterone is low and estrogen is high.

However, that doesn’t mean I shouldn’t try. I never know what we might find. Even a blind squirrel finds a nut every so often!

The ideal outcome would be “normal” levels for both across a nice cross section of men and women who are heavy drinkers of Soylent.


You could fund it through like these guys are doing, if you think it might help.

That may be more official than you are going for, though.


Thanks for the tip. I’ll check it out and give it some consideration. Perhaps I will go this route if we don’t get a lot of feedback here. I wonder how many people test their blood quarterly like I do? I feel great on Soylent, but it’s still a good idea to keep an eye on things just in case. In fact, I think this will become a lifelong practice for me. It’s cool to get a look under the hood, and useful to track my health over time.


I love the idea and hope that we can find people to test it. Not to rain on your parade, but I’ve never had my blood tested, much less quarterly. Is that something people do?


@gambit Not most people for sure, but in this age of the “quantified self” it is becoming more prevalent. It seems like something insurance companies would be all for, as they could catch problems early and save a bunch of money. Then again, I am assuming they want to keep me alive… :smiling_imp:

I get mine done through insurance because my doctor is on board with monitoring my health now that I am 80%+ Soylent. If he decides not to back me any more I would just go to one of these services.

Someone on here told me about They offer good prices, and you can use it for free to track results even if you don’t get the blood work done by them.

There is also, which a buddy of mine uses.


Here’s one more article on HuffPo in defense of Soy. It’s amazing how powerful the mob mentality is around nutrition fears. They are like chimps in the jungle, once one starts screaming, they all start screaming, and keeping doing so even if the threat was only potential or is already long gone.


Ah, yes, well I don’t go to doctors either, so there might be a correlation there.


Don’t forget to take hormone changes in men throughout the day into account. :sweat_smile: From what I heard, our levels rise and fall multiple times each day.


Will do. I will attempt to control for this by drawing blood first thing in the morning. As long as the rise & fall are not random, then this should work.


:sweat_smile: they should be the highest in the morning. That is what I heard at least.


[quote=“Woodster, post:8, topic:24817”]Here’s one more article on HuffPo in defense of Soy. It’s amazing how powerful the mob mentality is around nutrition fears.[/quote]I don’t think it’s nutrition fears so much as it is male insecurity.


Easy there…no hitting below the belt (literally and figuratively).


I am 52 and have panhypopituitarism i.e., hypothyroidism, hypogonadism & no adrenal function. I take hydrocortisone, armour, synthroid and testosterone cypinate to control my hormone levels. I get labwork done every six months to ensure they are in the appropriate ranges and my last lab was October 2015. My next one will be in March or maybe April 2016 due to my work schedule. BTW, I will have been consuming 2.0 3x daily for the entire 6 month period prior to my March/April labwork.

I love Soylent 2.0. Soylent 1.0 to 1.2 made me way to gassy, so I didn’t consume it regularly. I ate 1.3 & 1.4 (no gas issues with these versions) twice a day until 2.0 initially became available 9/15 and I now consume three (2.0) bottles everyday, I have a “normal” dinner with my wife. I have not had a single issue with my testosterone, estrogen or thyroid levels while consuming any version of Soylent.


Just thought I’d check back and let you all know that I my recent blood test came back and my Testosterone levels are normal. I had a 10.63, which is on the high side of the reference range of 1.14-15.93. Seems like after nearly a year on 60% to 80% Soylent, it is not impacting Testosterone. I’ll keep an eye on it, but maybe only once a year going forward.


@Woodster , How much was it before?


The OP seems to indicate this is the first time he tested it, so no prior data.


So @Woodster there is no way to be sure it hasnt impacted your testosterone. Also you must be on 1.5 not 2.0 most of the time, since you said you were consuming soylent since a year. RL needs to look into the impact 2.0 might have on testosterone levels. Run some tests on those beta testers it has.


I had blood work done after 1.2 years of a 60% Soylent diet (v1.0 through v1.5, as they were released). My serum testosterone was 939 ng/dL, with the reference interval being between 348 - 1197. I’ve only recently added 2.0 to the mix, so I don’t have any data on that.

FYI, the only thing that came in low was Vitamin D: mine was 15.8 ng/mL, with the reference interval being between 30.0 - 100.0. That surprised me. I now take a D3/K2 supplement daily.