As a beauty therapist with more than 25 years' experience, I'm used to my clients confiding in me some of their most intimate secrets.
Rather like a hairdresser, the hour - sometimes more - I spend administering treatments helps form an intimate bond.
Marital woes, job pressures and money troubles, I've heard them all, and it is my job to lend a sympathetic, non-judgmental ear, and never breathe a word to anyone.
In recent years though, I've noticed a recurring complaint that's started to worry me: many of the women I see regularly said the physical intimacy had all but disappeared from their relationships.
In most cases, many of them just didn't seem to feel like making love - or to use the words of one particular client: "I can't remember when the mood last took me," reports the Daily Mail.
Another woman - a thirty-something beauty - told me that even when she tried to summon up interest, her husband didn't read the signals.
It left me profoundly puzzled. After all, these were successful, healthy women who kept themselves in good shape. Some were only in their late 20s, so this wasn't a case of midlife malaise.
Before long, I spotted something they all had in common. They'd all been having Botox injections for years, some more than they needed.
Yes, it had smoothed away some of their lines, but in the process it seemed to have taken something else with it as well - their ability to show their thoughts and their feelings. In short, even if they felt desire, their frozen faces weren't able to communicate it.
It struck me as a terrible irony: that the thing these ladies were doing to delay the ageing process and make themselves more attractive seemed to be having the opposite effect.
Instead of enhancing their sexual life, their heavy Botox use seemed to be sabotaging it.
Don't get me wrong, I'm not against Botox altogether. Administered with a light touch and in the right places, it can be a wonderful thing.
But could heavy use be ruining women's sex drives? Intrigued, I started to do more research. For those who don't know, Botulinium toxin works by blocking the release of neurotransmitters in muscles, causing paralysis forcing them to relax, and creating a smoother skin surface.
Approved for cosmetic use since 2002, nowadays it is the most popular, non-surgical cosmetic procedure in Britain, with millions of people - mostly women - having the injections every year.
It has many different trade names, and can cost between £150 to £350 per session. The treatment can be effective, but heavy users are left in the curious situation where their brain might think to smile or frown, but the face can't put those feelings into effect.
It's not a massive leap from there to understand that this is going to affect your mood. If you can't exercise your smile glands properly, then you are not going to be able to release the endorphins that make you feel sensual and alive. What could be sadder than that, however lovely you look on the outside?
Further evidence of the way Botox can numb all the senses, meanwhile, was unfolding in my salon.
As part of my facial, I use a beautiful "dream oil", a vivid concoction with base notes of that most fragrant of flowers, jasmine.
I noticed my clients who were heavy users of Botox were less susceptible to the smell - if at all. There's no physiological reason for this: muscles, not sensory receptors, are being injected by Botox, leading me to conclude that their very mood is stymied.
They just weren't receptive to life's pleasures any more. Is it any wonder their romantic lives were suffering?
I'm not the only one to think there's a link.
Psychologist Jo Coker, who specialises in relationships, says: "The very fact that women will choose to use Botox suggests that they are already uneasy in their own skin.
"Botox does freeze wrinkles, but in doing so it acts as a mask on the face. What women don't realise is that, with an expressionless face, they're missing out on a crucial aspect of what it is to be human.
"They're not firing the feel good hormones. Oxytocin is vital to our wellbeing.
"When we recognise, judging by someone's facial expression, that they're interested in us or responding in a positive way, our brain releases this hormone.
"It not only makes us feel good, but helps us form a lasting bond with our partners. No wonder these women aren't having sex."
And I believe too much Botox can affect the way we interact with people day to day, too.
Take a female celebrity I saw for regular facials. She has always been open about her use of Botox. As the months went by, I felt her face was starting to lose its softness and, as a result, she seemed to be struggling to connect with her TV audience.
It struck me that the two things were linked - and sure enough, she confided in me she felt she'd overdone the Botox and was going to stop. The following year, she came into her own and her television career took off.
Perhaps that was at the back of my mind, too, when I realised my clients were bemoaning the lack of intimacy with their husbands.
For all too often though, that first injection of Botox proves to be the thin end of a big wedge. Before you know it, you start to see the telltale high eyebrows, overly smooth forehead and "frozen" expression that we have seen on countless celebrities.
Sometimes this can happen the first time, as it did to me on the one and only occasion I tried it, 13 years ago. The overall effect was best summed up by my sister when, months later, the effects had worn off.
"Thank God it's gone - you looked like Mr Spock," she said.
Psychologist Dr Michael Sinclair believes that we are instinctively wary of "perfect" looking people.
"Believe it or not, people warm to imperfect people. If we're concealing ourselves, how can we expect anyone one else to fall in love with us?"
Now, more than a decade later, I pride myself on looking good for my age, 51, without resorting to artifice. I have a good skincare regime, I eat well, don't smoke and drink in moderation.
It makes me sad that women can't be more accepting of the face that Nature has given them. So many of them fall into the trap of thinking their partners want a perfect mannequin when actually they want interaction.
That's why, when clients have mentioned that they've gone off sex, I have suggested they lighten up on the Botox.
In every single case, months down the line, they said their relationships had improved.
Happily, I think the mood is shifting. Subtlety seems to be the watchword, while even the most fervent Botox fans among my clients are using it less and less.
I genuinely think none of them look any worse for it - and I guarantee they will be having a better time in the bedroom as a result.