Am I Alone? The Soy in Soylent Messed Me Up


I have had endocrine/hormone issues for a while, but they’ve more or less stabilized in the past few years. The net effect of this is that I regularly get hormone tests by my endocrinologist. When I started taking Soylent 2.0 the estrogen in my system crashed hard. I had to stop taking Soylent 2.0 and my levels are mostly back to normal now. It’s a shame because the glycemic impact of Soylent 2.0 and the overall ability to manage my calories closer really helped me lose weight.

Considering that there are 52 mg of soy isoflavones in one serving of Soylent, that means that an average Soylent consumer would be consuming 260 mg of isoflavones a day. I recognize a lot of people think the science is still out on phytoestrogens, but is it? Has Soylent done the science? Can we get links? I looked around and everything seems to agree that Soy is an endocrine disruptor.

Iowa State Univ has done some science and they recommend that people consume less than 100 mg. Am I the only one that has been negatively impacted by consuming Soylent 2.0? Has anyone else that has taken 2.0 experienced estrogen enhancing or negation? I have read some posts but, I can’t be the only one…


Can you be more specific about your issue? What were the levels measured before and after Soylent 2.0. I assume you had some blood tests done? What were your symptoms? It seems you had a pre existing problem that reoccured because of Soylent if I understood correctly? If I understand the science correctly… Soy wont increase your estrogen levels at all… If anything, they may increase the levels of the phytoestrogen or what they were called, which is different but may have similar properties.


My estrogen went from crazy high to about half what it normally is. I’m not going to give numbers (sorry guys!).

Symptoms: inability to sleep, joint pain, lack of libido. There are other things too that I personally attribute to it but might not be problems so I’m not getting into those.


Your first message mentions weight loss and your second message mentions weight gain.

How long were you consuming 2.0 and in what amounts?


Thanks. I forgot that it was weight loss not gain. Objectively lost 15 pounds. I didn’t have the larger chest or sensitive nipple problems. I had it from Sept 2015 to Dec 2015. I have it recorded somewhere. I was taking 3-5 bottles a day with no particular goal. I think I averaged 4 bottles.


:sweat_smile: I am just going to point out something that will make the whole community of anti soy cry [quote=“ytfsic, post:3, topic:25174”]
My estrogen went from crazy high to about half what it normally is

If soy is indeed the reason for your lower estrogen levels, then the anti soy movement has officially lost… since their claim is that soy increases estrogen levels. GG anti soy movement


OK let’s talk about that. Soy is a phytoestrogen, meaning it behaves as estrogen. It is adding extra estrogen to your system. In that way it increases your estrogen. Your body will produce less estrogen as a result. I think this is why it is called a disruptor. My estrogen tests would not test “phytoestrogen levels” only estrogen levels. I think one of us is misunderstanding something. I’m going to guess that since I have an endocrinologist explaining things to me that it’s not likely me, although it is quite possible that I misunderstand why my endo is very anti-soy for people with hormone sensitivities like myself.


Well, I did find this now that I looked into it further,

…Soy consumption has been suggested to exert potentially cancer-preventive effects in premenopausal women, such as increased menstrual cycle length and sex hormone-binding globulin levels and decreased estrogen levels…

I am sure your doctor knows what he/she is talking about, but I am curious about how much the actual difference/affect is… half of your normal estrogen levels sounds extreme.


Can I ask you a big favor? If you did have blood tests done, consider giving the results to Rosa Labs (the Soylent team) and if your doctor considers those results to be negative/bad… Then the team should work towards a version with less phytroestrogen purely for that reason.

(You can get soy protein with reduced levels of the phytoestrogen, though the question is how much more expensive that would be)


When I started Soylent 2.0 I had read through all of the forum armchair scientist discussions and saw that people were disputing the reliability of the ‘Soy is disruptive’ conclusions. Specifically for me was that one study had only one participant that was negatively impact by soy. I thought it was particularly curious that so few people were actually impacted by soy and wrote it off. To my own detriment, I went against my endo’s advice and started Soylent 2.0, thinking that I would have the regular periodic tests and be fine.

I didn’t start this thread to re-ignite or re-fuel the “soy is evil” discussion, although I can see how the original post did sound like I was opening that can all over again. Although I can see the case both ways, I couldn’t give a darn whether other people think soy is evil because (to me) after I started drinking Soylent 2.0, my numbers went way out whack.

I WOULD like to know if other people have the same experience as me, because I don’t trust most doctors to know what they’re talking about (even though my endo has been surprisingly reliable) and I’d like to understand whether there are commonalities between my experience and ANYONE else. I find it strange that I would have such a strong reaction and then I would watch the forums and not hear anyone else saying they’ve experienced the same thing. Surely I’m not THAT much of a unicorn.

I have waited a few months to post anything because 1) I don’t want to have to argue that what has happened to me has happened to me 2) I wasn’t sure I was back to normal (spoiler: just got the March test results back and I haven’t stabilized) 3) there’s still this hope in the back of my head that it wasn’t soy and it was something else.

Now as far as your favor/request: providing my test results would be of little value. Here’s why I think that:

  1. Although I can anecdotally share my results, my situation is far from normal. I have been on managed hormones since 2011.
  2. I did not record my Soylent intake and my Soylent intake did vary day-to-day
  3. (Related to 1) All other variables were not controlled by me.

I’d gladly share my numbers with Rosa if I thought it would actually provide value. Right now all I want to know was “was I a unicorn?” or is this something we can narrow down? If this becomes a discussion on whether there are “evils of soy” or not, and this thread gets lost to trollery (not calling you a troll, saying that there’s a tendency for the internet to do that) then no one will ever come forward. I almost didn’t come forward because I didn’t want to have to explain my experience rather I wanted to see if anyone else had the same experience. If lots of other people came forward it could help us affected people discuss our situations or it could help Rosa lock down some sort of warning or guidance so people that may experience issues don’t try it.

Rosa clearly knows that some people are concerned about soy isoflavones since they disclose isoflavone levels on their website. Their stated goal is to eventually get off Soy long term. I really hope it’s sooner than later because I’d really really like to get back to an easy to manage low Glycemic Index/Glycemic Load diet with very controlled macronutrients and caloric values. If Rosa reaches out to me and wants to do a more controlled study I will speak with my endo and help them out. I am certain that just randomly giving them my test results from last year won’t be enough to be useful.


The number is almost exactly half. I’m not using hyperbole.


@conor I think this concern of females with specific hormone imbalance issues is valid, with the link I posted above mentioning that lower levels of estrogen being a possibility with phytoestrogen… Which seems even more likely with the high levels in a daily dose of 2.0… It is much more valid than some men being worried they will grow boobs. Pass it along to the team please :sweat_smile:


They have already read the thread. :slight_smile:


Couldnt agree more.

20 characters.


Also because some people are looking to get soy isoflavones into their diet, and Rosa Labs wants them to know Soylent 2.0 is a source.

I’m not discounting your position or experience - just reminding you that a fair number of people are looking for it. At least Rosa Labs is disclosing.


I do appreciate the disclosure, at least. In that we are in agreement.


That is not how it works, if you take an exogenous hormone the endogenous production is downregulated but the net effect is positive.

In other words, the phytoestrogens are acting in behalf of your own estrogen, and very potently since they are having a huge effect on the production of your own estrogen, THAT ACTUALLY VALIDATES THE ANTISOY MOVEMENT.

Edit: Aaand that has already been said.


We’re talking about soy isoflavones, which are not an exogenous hormone. Isoflavones mimic estrogen by fitting into some estrogen receptors, but isoflavones are not actual hormone - exogenous hormone would have much more potent effect in the body.

Isoflavone will not register as estrogen in a blood test, regardless the level you take. Exogenous estrogen, on the other hand, will result in measurable estrogen in the blood. Like you say, if you take more than enough exogenous estrogen to compensate for the decline in endogenous estrogen, then the net effect on estrogen levels can be positive… but that is simply not true for isoflavones, which aren’t estrogens or hormones at all.

[quote=“Neometheus, post:18, topic:25174”]
In other words, the phytoestrogens are acting in behalf of your own estrogen, and very potently since they are having a huge effect on the production of your own estrogen, THAT ACTUALLY VALIDATES THE ANTISOY MOVEMENT. [/quote]

Soy isoflavones are well-described as having only a weak estrogenic effect.

Isoflavone phystoestrogens don’t typically increase estrogen levels - they tend to bring them down. They are mild inhibitors of aromatase, which converts androgen to estrogen. With less aromatase, you end up with less estrogen. (Flavones are typically stronger inhibitors of aromatase than isoflavones - see Molecular basis of the inhibition of human aromatase (estrogen synthetase) by flavone and isoflavone phytoestrogens: A site-directed mutagenesis study.

The usual knock on soy isoflavones is fear of their direct estrogenic activity. It’s not estrogen, but can bind to some estrogen receptors because of similarity… but in some cases, when it binds, it acts like estrogen, while in other cases, it binds to the receptor but doesn’t work, so it effectively blocks real estrogen. These effects, however, appear to be quite mild in all the studies that are done. People with hormone imbalances may be more sensitive, however - and this includes bodybuilders who have actively disrupted their hormonal funciton.


Soy isoflavones are well-described as having only a weak estrogenic effect.

Except that is noy true, we know little about the effects of isoflavones and most evidence says they act similarly to SERMs but we don’t have enough data to back your statement.


I’ll ask you to check on how good your sources are.

Most of the “we have no idea” types of articles are in the lay press, typically pseudo-scientific press that pushes naturalistic ideas or is hawking fitness “news” and products.

Most of the serious literature, including the stuff from academia, has concluded the effects are weak. Example:

Studies on isolated extracts of specific isoflavones find that some of them are strong, but that’s not representative of the general effect from soy or soy food products.