That's a lot of shampoo! Can you tell him hie's using too much? I think it took me a while to realize that you don't need several giant handfuls of shampoo per wash. 

It's one of those trivial things that isn't trivial - SD was taking our shampoo and boyd wash to her mother's house and I shut it down. Like, F that. I don't subsidize your Mother's house. I also hide all of my stuff in my room because my products are expensive and I'm not using the cheap stuff just because kids can't keep their hands off my stuff. 

That’s ridiculous.  I use a lot of shampoo because my shoulder length hair that I wash every other day is very thick. It can be hard to get my scalp clean without a lot of shampoo to get down to the roots. 

But even I do not begin to go through shampoo at that rate.  When I had short hair I only used like a teaspoon or so, but I washed my hair every day then. 

Give your SS a bar of cheap soap to use if he can’t control his shampoo consumption. 

SS is 19. He should have a job and provide  ( buy and pay for) his personal hygiene products. At this age parents should not be providing them.

Buy him a bottle of lube and place it beside the shampoo.

The men I've lived with over time all had short hair, including my husbsnd. One bottle of ANY shampoo lasts many, many months for them. I have very thick hair & go through it much faster, but any given bottle lasts me several weeks. 

So maybe do a little tutorial with him. Also, make sure he's not using shampoo as bodywash! 

Is he drinking it?  Even if he is using it as body wash as well I can't imagine going through it that fast.  I would have his father just ask him what the deal is.  And there is no reason that you have to keep buying it on a regular basis.  People forget things at the store all the time.  He is old enough to purchase his own toiletries if he runs out.

That's a lot for short hair.

let is run out and when he asks for more, tell him to buy his own and ask your DH to please do the same.

SDs both use wayyyyyyyy too much shampoo and conditioner. I taught them how to wash their hair (ages 7 and 9!) But only to the extent I had any authority, you know how it goes. And never does anyone listen to me.

So I gave up buying that stuff years ago. DH has to.

Sounds like he's using it as bodywash, too. 

DH can give SS a capful of 'poo before every shower, tell him to cut usage waaaaay down, or stop supplying it.

have very thick and in the case of oldest DD, long hair (as do I) and we don't go through that much shampoo and conditioner. We only use a lot of conditioner when we deep condition once a month as oldest DD has so much hair she can use half a bottle for deep conditioning. My husband has short hair and a bottle of shampoo lasts for months. 

He needs to pay for his own toiletries. Whether your husband gives him an allowance, spending money, or if he has a job...whatever. Toiletries need to be on him. 

I buy the large 1 ltr KMS bottles for myself, for around $40, and I've had the same one for almost a year! I'll probably need to buy more in a month or two. But nobody else touches my shampoo and conditioner.

SD7 gets dollar-store brand shampoo and bars of soap because otherwise, i'd be spending way too much. I try to explain to her how much she needs, but it goes in one ear and out the other. DH doesn't do the budgeting so he doesn't get why it matters.

Prior to this, I was buying $3-4 bottles of shampoo AND $3-4 bottles of body wash once every 2 weeks just for her to use. That's $12 - 16 a month in shampoo and body wash alone for one little girl. No way I'm doing that... It works out to be more expensive than my high quality stuff! 

because he doesn't have employment.....have your husband get him a Greenlight card or a similar product and then put his money for toiletries and other things on the card and make him responsible for it. I have Greenlight for my two teens still at home. Their allowance goes on that card and they have things they must do to get their allowance. They also have ways of earning extra money. BUT they have to pay for their toiletries, extras, and most outings with friends (school dances I pay for) with that money. I do provide extras of certain toiletries if I have couponed and I pay for female items as well but I don't buy them their specific brands of shampoo, conditioner, body wash etc. The 17 year old also has to pay for her extra makeup or clothing items as she is a bit of a clothing and makeup snob. I even put her school clothes budget on it and told her she could buy one outfit or 12 but that was all she was getting. 

These cards also allow you to track where they are spending and insist on savings. It has been awesome for teaching the teens how to budget. 

He may be using shampoo for masturbatory purposes as well as washing his hair and body. Ick.

Have you tried adding water to the bottle to dilute the shampoo and make it to further? I have a hairdresser friend who does this with her own high end shampoo.

Have you tried letting him run out of product? Would that encourage him to use it more sparingly?

SS16 uses way too much shampoo as well  Must be an autistic thing. So we just buy him cheap shampoos and let him go for it.   Store brands in England are £1 or less so it's no biggie.

He doesn't touch our shampoos so that's not an issue.   It's just food we have to hide...

He is 19 . Let him buy his own shampoo.

Buy suave or dollar store shampoo.  when it goes to half a bottle, fill it up with water, shake and hilarity ensues!  Make sure you hide the good stuff.

I didn't have this problem because none of my skids washed. used toothpaste, soap,  shampoo nor wipe themselves after using the bathroom nor did they flush.  What I did do to save money was to put store brand crap into brand name boxes, jars and container because he used to bitch about me buying "cheap stuff" for his angels.  ( yeah he called them that...made me want to puke)

Meanwhile, child support was all of his paycheck except for maybe 20 bucks a week so I was expected to support his three brats on my salary as they ran up the utility bill and the food bill sky high.

OP buy the cheapest shampoo you can find. In a decent voice i would have no problem saying ,,,"this is your shampoo from  March 1 until April 1....use it wisely OR buy your own"

He is not a toddler or 10 year old where you have to be very careful what to say. He is 19 and you can bet I would tell anyone who was living in my home what i wrote above. I don't care who the heck it is.